Dr Mobeus
Potato and Leek Gratin
Potato and leek gratin is what happens when you take the cheapest root vegetable in the shop and dress it up enough to serve at a dinner party. Leeks and potatoes are two of the best value ingredients in any UK supermarket and when you bake them together in a creamy cheese sauce they become something genuinely luxurious. At 58p a portion it costs a fraction of what a restaurant would charge for dauphinoise potatoes. The leeks add a sweet, mild onion flavour that works perfectly with the creamy sauce. This is comfort food at its most economical and its most satisfying.
Potato and Leek Gratin
Ingredients
Method
- Preheat the oven to 190C/170C fan/Gas 5. Grease a medium ovenproof dish with a little butter.
- Melt the butter in a saucepan over medium heat. Add the leeks and onion, cook gently for 8 minutes until soft and sweet. Remove from the pan and set aside.
- In the same pan, add the flour and stir for 1 minute. Gradually whisk in the milk, stirring until you have a smooth sauce. Cook for 3-4 minutes until thickened. Stir in half the cheese, the thyme and some salt, pepper and nutmeg if using.
- Layer half the sliced potatoes in the dish. Spread the leek and onion mixture over the top. Layer the remaining potatoes on top.
- Pour the cheese sauce evenly over the potatoes. Scatter the remaining cheese on top.
- Bake for 40-45 minutes until the top is golden and bubbling and the potatoes are tender when pierced with a knife. Let it rest for 5 minutes before serving.
Tips and Variations
Slice the potatoes as thin as you can – a mandoline is ideal but a sharp knife works. Let the gratin rest for 5 minutes before serving or it will be too runny. Add a layer of cooked ham between the potatoes to make it more substantial. This reheats well the next day and actually tastes better for it.
