Delia Smith Boulangere Potatoes​ Recipe​

These boulangère potatoes are a classic, roast-friendly side dish of thinly sliced potatoes and sweet onions baked slowly in stock until meltingly tender with a golden, buttery top. The texture is soft and spoonable underneath with crisp edges on top, and the flavour is deeply savoury without needing much effort. It is an easy, reliable bake that mostly looks after itself in the oven. Total time is about 1 hour 40 minutes, including prep.

Table of Contents

• Recipe Card
• Ingredients
• How to Make Boulangère Potatoes
• Tips for Perfect Results
• Serving Suggestions
• Storage
• Nutrition
• FAQs

Ingredients

For the potato and onion layers

• 1.2 kg floury potatoes (Maris Piper or King Edward), peeled
• 450 g onions, peeled and thinly sliced
• 1 tsp fine salt (adjust to your stock)
• 1/2 tsp freshly ground black pepper
• 1 tsp fresh thyme leaves (optional)

For baking

• 700 ml hot chicken or beef stock
• 2 tbsp olive oil or 30 g butter (for softening the onions)
• 50 g unsalted butter, cut into small pieces (for the top)

To prepare the dish

• Butter, for greasing the baking dish

How to Make Boulangère Potatoes

• Prepare the oven: Preheat the oven to 200°C or 180°C fan. Place a shelf in the middle of the oven so the dish bakes evenly and the top browns without scorching.
• Grease the dish: Butter a large baking dish (roughly 30 x 20cm). A wide dish gives you more golden top, which is never a bad thing.
• Slice the potatoes: Slice the potatoes thinly, about 2–3mm. If you can, use a mandoline for neat layers. Keep the slices in cold water while you deal with the onions to stop them browning.
• Soften the onions: Warm the olive oil (or 30 g butter) in a frying pan over medium heat. Add the onions with a pinch of salt and cook for 10–12 minutes until soft, sweet, and lightly golden. You want them silky, not browned and bitter.
• Drain and dry: Drain the potatoes well and pat them dry with a clean tea towel or kitchen paper. This helps the top layer colour and stops the dish turning watery.
• Layer everything: Add half the potatoes to the dish, seasoning lightly with salt and pepper. Spoon the onions over in an even layer, then top with the remaining potatoes. Sprinkle over thyme, if using.
• Add the stock and butter: Pour the hot stock carefully down the side of the dish. The stock should come most of the way up the potatoes without completely submerging them. Dot the top with the 50 g butter.
• Bake covered: Cover the dish tightly with foil and bake for 45 minutes. This stage gently cooks the potatoes through and keeps the moisture in.
• Finish uncovered: Remove the foil and bake for another 30–40 minutes until the top is golden and the potatoes are fully tender when pierced with a knife. If you want a deeper colour, pop it under the grill for 2–3 minutes, keeping a close eye.
• Cool and serve: Let the dish rest for 10 minutes before serving. The layers settle and the stock thickens slightly, so you get neat scoops instead of a soupy slide.

Tips for Perfect Results

Why are my boulangère potatoes still hard in the middle?

This usually comes down to thick slices or not enough covered baking time. Slice the potatoes evenly (2–3mm) and make sure the dish is tightly covered with foil for the first 45 minutes. If they are still firm after uncovering, add a splash more hot stock, re-cover for 10–15 minutes, then uncover again to brown.

How do I stop the onions from tasting bitter?

Cook them slowly until soft and pale golden, but do not rush them into browning. Medium heat and a small pinch of salt helps them release moisture and sweeten. If they catch and darken, the bitterness will carry through the whole dish.

What stock should I use for the best flavour?

Chicken stock is gentle and works with almost everything. Beef stock makes the dish brilliant alongside roast beef, lamb, or sausages. Use a stock you would happily drink, because the potatoes soak up every bit of it.

How can I get a really golden, crisp top?

Dry the potato slices well, dot with butter generously, and bake uncovered long enough for the surface to dry and colour. If your oven runs cool, finish with a short blast under the grill, but stay close because it can go from golden to burnt quickly.

Serving Suggestions

• Serve with roast chicken and a simple green salad.
• Pair with roast beef, gravy, and buttered greens.
• Offer alongside sausages and caramelised cabbage.
• Make it a vegetarian plate with roasted carrots and a mustardy lentil salad.

Storage

Room Temperature

Let the dish cool, then keep it covered at room temperature for up to 2 hours. After that, refrigerate for food safety.

Refrigerator

Store in an airtight container or cover the baking dish tightly and refrigerate for up to 3 days. Reheat covered in a 180°C oven for 20–25 minutes until piping hot, then uncover for 5 minutes to re-crisp the top.

Freezing

You can freeze leftovers, although the texture will be a little softer after thawing. Cool completely, portion into airtight containers, and freeze for up to 2 months. Thaw overnight in the fridge, then reheat covered at 180°C until hot all the way through.

Nutrition

• Calories: 260 kcal
• Carbohydrates: 39 g
• Protein: 6 g
• Fat: 10 g
• Saturated Fat: 5 g
• Sodium: 520 mg

Disclaimer: Nutrition values are estimates and will vary depending on the stock used, exact potato size, and portion size.

FAQs