Traditional Welsh Onion Cake (Teisen Nionod) Recipe

I absolutely adore sharing this Traditional Welsh Onion Cake (Teisen Nionod) Recipe with friends because it’s one of those dishes that feels like a warm hug from Welsh heritage. Layers of tender potatoes, sweet onions, and leeks come together with melted butter and sharp mature Cheddar, baked to golden perfection. The flavors marry beautifully, creating something comforting yet special that I always look forward to making and savoring during cozy meals.

Why You'll Love This Traditional Welsh Onion Cake (Teisen Nionod) Recipe

What I truly love about this recipe is how the flavors are so wonderfully balanced—the sweetness of the onions mingles with the earthy potatoes and the subtle bite from the mature Cheddar, all kissed by fragrant fresh thyme. It’s a simple yet incredibly flavorful dish that never fails to delight the taste buds. The crispy golden edges contrast perfectly with the soft, layered interior, and I find it deeply satisfying every time I dig in.

Another thing that gets me excited about this Traditional Welsh Onion Cake (Teisen Nionod) Recipe is how straightforward it is to prepare, even though it looks impressively layered. Once you’ve sliced the veggies thinly and assembled the layers, the oven does all the magic while you relax or prepare other parts of your meal. It’s perfect for weeknight dinners, family gatherings, or whenever you want a comforting side that’s a little different from the usual. I promise, it really stands out on the plate and in your memory!

Ingredients You'll Need

The ingredients for this Traditional Welsh Onion Cake (Teisen Nionod) Recipe are beautifully simple yet essential—each brings its own touch to the final flavor, texture, and aroma of the dish. From the sweetness of the onions and leeks to the buttery richness and sharp Cheddar, everything combines effortlessly.

• Onions: I choose medium onions for their perfect balance of sweetness and body, peeled and sliced thinly to meld seamlessly into the layers.
• Potatoes: Red, Désirée, or Maris Piper potatoes work well for their creamy texture and ability to crisp gently on top.
• Leek: Adds a lovely mild onion flavor and a fresh green touch; make sure to wash it well and slice thinly.
• Unsalted Butter: Melted and used generously to coat the potatoes and brush the top, giving that irresistible golden finish.
• Mature Cheddar: This brings sharpness and richness, melting into the layers and adding savory depth you won’t want to skip.
• Fresh Thyme Leaves: The subtle herbal note uplifts the earthy flavors and adds a fragrant complexity.
• Salt and Pepper: Season each layer lightly to ensure every bite is flavorful and balanced.

Directions

Step 1: Preheat your oven to 220°C (200°C fan) or Gas Mark 6. This high heat is crucial for that initial gentle cooking under foil.

Step 2: Use a mandoline or a sharp knife to slice your onions, potatoes, and leeks into thin 2-3mm rounds. Thin slices are key to achieving those soft, even layers.

Step 3: Grease a deep 23-24cm round pie dish or cake tin thoroughly with some butter. This helps the cake release easily and adds flavor to the edges.

Step 4: Toss your potato slices with most of the melted butter so they’re nicely coated but not drenched. Set a little butter aside for basting later.

Step 5: Start layering by placing a layer of potato slices on the dish base, seasoning lightly with salt and pepper. Follow with a layer of onions and then leeks. Sprinkle some grated Cheddar and fresh thyme leaves over this layer. Continue repeating layers until all ingredients are used, finishing with potatoes on top. Press gently on each layer to compact them neatly.

Step 6: Brush the top potato layer with the remaining melted butter. Pour any leftover butter over the whole cake in the dish for extra richness.

Step 7: Cover the dish tightly with foil and bake at 220°C for 1 hour. This slow cook under foil helps the vegetables soften perfectly without drying out.

Step 8: Remove the foil and brush the surface again with the reserved butter. Reduce the oven temperature to 200°C (180°C fan) or Gas Mark 6 and bake uncovered for another 30 minutes. The top should turn deeply golden and crisp up beautifully.

Step 9: Let the onion cake rest for 10 minutes once it’s out of the oven. This resting time helps it set, so it slices nicely. Garnish with some extra fresh thyme leaves for that finishing touch before serving.

Servings and Timing

This Traditional Welsh Onion Cake (Teisen Nionod) Recipe makes about 4 generous servings, perfect for sharing with family or friends. The prep time is roughly 20-30 minutes, mostly spent slicing the vegetables and assembling the layers. Bake time totals 1 hour and 30 minutes, including the covered and uncovered stages. Don’t forget the 10-minute resting period before slicing, which helps the cake hold its shape nicely.

How to Serve This Traditional Welsh Onion Cake (Teisen Nionod) Recipe

When I serve this onion cake, I love pairing it with a lightly dressed green salad to add freshness and a bit of crunch that contrasts the tender layers. For a heartier option, it’s fantastic alongside roast meats like chicken or pork, or even sausages. The savory richness and herbs complement traditional British roasts beautifully. On casual days, I often enjoy it as a main with just some simple steamed vegetables or a tangy beetroot salad.

Presentation-wise, I slice it into wedges just like a cake. Serving it warm is my favorite since the cheese is melty and the butter flavor shines through most vividly. You can garnish with a little extra thyme, or if you’re feeling indulgent, some crème fraîche or a dollop of sour cream on the side adds a lovely creamy touch.

As for drinks, I like to keep it simple—something light and crisp like a dry white wine or a refreshing sparkling water with lemon works beautifully. For cozy evenings, a glass of robust cider fits the rustic vibe perfectly. This onion cake really shines at family dinners, weekend gatherings, or when you want something special yet comforting on the table.

Variations

I often experiment with this onion cake to suit different tastes or dietary needs. For a gluten-free version, the recipe easily works as is since it uses no flour or bread. Vegan friends can swap the butter for a plant-based alternative and substitute the Cheddar with vegan cheese—though expect a slightly different but still delicious flavor.

You can also play around with the herbs. Fresh rosemary or sage are lovely alternatives or additions to thyme, adding a woodsy, aromatic quality. Sometimes I include a sprinkle of smoked paprika or nutmeg in the layers for a subtle warmth that pairs really well with the onions and potatoes.

If you’re pressed for time, you can try a skillet method by layering the ingredients in a heavy ovenproof pan and finishing on the stove top before transferring it to the oven to crisp the top. Though it won’t be quite the same as the traditional layered bake, it’s a great shortcut that still delivers rich, comforting flavors.

Storage and Reheating

Storing Leftovers

I keep leftover Traditional Welsh Onion Cake (Teisen Nionod) refrigerated in an airtight container or wrapped tightly with cling film. It stays good for up to 3 days, making it convenient for quick lunches or dinners. When properly stored, the flavors even mellow and deepen a little overnight.

Freezing

You can freeze this onion cake but it’s best to do so before baking. Assemble the cake in a freezer-safe dish, wrap it well with foil and cling film to avoid freezer burn, and it can keep for up to 2 months. When ready to enjoy, thaw overnight in the fridge and bake as directed, adding a little extra time for reheating and crisping.

Reheating

To reheat, I prefer using the oven to restore that crisp top and tender inside. Cover the cake with foil to prevent drying out, warming at around 160°C for 20-30 minutes until heated through. Avoid microwaving if possible, as it tends to make the potato layers soggy instead of maintaining the delightful textures.

FAQs

Can I prepare this Traditional Welsh Onion Cake (Teisen Nionod) Recipe ahead of time?

Absolutely! You can slice and layer the vegetables the day before and keep the assembled cake covered in the fridge. Just add the finishing melted butter just before you bake it. This makes it a great recipe for planning meals ahead.

What type of potatoes work best in this recipe?

I recommend waxy or all-purpose potatoes like Red, Désirée, or Maris Piper because they hold their shape well when baked and don’t become too mushy. Avoid very starchy potatoes as they can break down too much.

Is it necessary to use fresh thyme, or can I use dried herbs?

Fresh thyme really adds a bright, subtle herbal aroma that pairs perfectly with the onions and cheese. If you only have dried, use about half the quantity, but I always encourage using fresh whenever possible for the best flavor.

Can I make this recipe vegan?

Yes, by substituting unsalted butter with a plant-based spread and using a vegan cheese alternative, you can easily adapt this recipe. The texture and flavor will be slightly different but still delicious and satisfying.

How thick should I slice the vegetables?

Slicing to about 2-3mm thickness is ideal. Thin slices ensure the layers cook evenly and become tender without drying out, while still holding together nicely for that beautiful layered effect.

Conclusion

I truly hope you give this Traditional Welsh Onion Cake (Teisen Nionod) Recipe a try—it’s such a heartfelt dish with roots in tradition and warmth. The combination of simple, humble ingredients transformed into something so flavorful always makes it a winner around my table. It’s a cozy, comforting treat I know will bring a special touch to your meals just as it does to mine.

Traditional Welsh Onion Cake (Teisen Nionod) Recipe

Print Recipe

Pin Recipe

5 Stars 4 Stars 3 Stars 2 Stars 1 Star

4.3 from 2 reviews

This Traditional Welsh Onion Cake, known as Teisen Nionod, is a classic and comforting layered potato dish featuring thinly sliced onions, leeks, and mature Cheddar cheese. Slow-baked until tender and golden, it makes a flavorful main or a perfect side to roast meats. The combination of butter, thyme, and sharp cheese enhances the natural sweetness of the vegetables, delivering a hearty and satisfying dish from Welsh culinary heritage.

• Author: Mira
• Prep Time: 45 minutes
• Cook Time: 1 hour 30 minutes
• Total Time: 2 hours 15 minutes
• Yield: 4 servings
• Category: Side Dish
• Method: Baking
• Cuisine: Welsh
• Diet: Vegetarian

Ingredients

Vegetables

• 3 medium onions (approx. 300g, peeled)
• 700g Red, Désirée or Maris Piper potatoes (peeled)
• 1 large leek (approx. 150g, washed, trimmed and halved lengthways)

Dairy & Butter

• 100g unsalted butter (melted, plus 1 tbsp melted butter for brushing)
• 150g mature Cheddar cheese (grated)

Herbs & Seasonings

• 2 tsp fresh thyme leaves
• Salt and pepper (to season)

Cook Mode Prevent your screen from going dark

Instructions

1. Preheat Oven: Preheat your oven to 220°C (200°C fan)/Gas Mark 6 to ensure it is hot enough for baking the onion cake.
2. Slice Vegetables: Using a mandoline or a sharp knife, slice the onions, potatoes, and leeks into thin rounds approximately 2-3mm thick for even cooking.
3. Prepare Dish: Grease a deep 23-24cm round pie dish or cake tin with butter to prevent sticking.
4. Coat Potatoes: Toss the potato slices in most of the melted butter until lightly coated. Reserve some butter for basting later.
5. Layer Vegetables: Arrange a layer of potato slices over the base of the dish, season lightly with salt and pepper, then add a layer of onions and leeks. Sprinkle some grated Cheddar and thyme leaves. Continue layering in this sequence, pressing down gently after each layer to compact the cake, finishing with a final layer of potatoes.
6. Top with Butter: Brush the top potato layer generously with the remaining melted butter and pour any leftover butter into the dish.
7. Bake Covered: Cover the dish with foil and bake in the preheated oven for 1 hour to soften the vegetables.
8. Uncover and Finish Baking: Remove the foil, brush the surface with the reserved 1 tablespoon of melted butter, reduce oven temperature to 200°C (180°C fan)/Gas Mark 6, and bake for an additional 30 minutes until the potatoes are tender and the top is crisp and golden.
9. Rest and Garnish: Let the onion cake rest for 10 minutes to set before garnishing with extra thyme leaves.
10. Serve: Serve warm as a main dish with a lightly dressed salad or as a side alongside roast meats or sausages.

Notes

• Using a mandoline ensures even thickness for uniform cooking of vegetable slices.
• Pressing down each layer helps the cake hold its shape and compacts the ingredients for a neat presentation.
• Adjust the seasoning between layers to balance flavors thoroughly.
• Allowing the cake to rest before serving lets the layers set for easier slicing.
• This dish can be prepared ahead and reheated gently in the oven before serving.