Classic Beef Lasagna

Finely chop the onion, carrot and celery into pieces of about 5 mm. Heat the olive oil in a wide, heavy-based pan or casserole over a medium heat, add the vegetables with a pinch of salt and cook for 10 to 12 minutes, stirring, until soft, sweet and golden at the edges. Add the crushed garlic and cook for 1 minute.

Turn the heat to high and add the mince. Break it up and let it sit for a couple of minutes between stirs so it browns rather than stews. Keep going for about 10 minutes, until all the liquid has gone and the meat is deeply browned. This browning is where most of the flavour comes from.

Stir in the tomato purée and cook for 2 minutes until it darkens. Pour in the wine, scrape up the base of the pan and let it bubble for about 3 minutes until nearly all of it has evaporated.

Add the tinned tomatoes, 200 ml of water, the bay leaves, oregano, 1 teaspoon of salt and plenty of pepper. Bring to a simmer, then turn the heat as low as it goes and cook, partly covered, for 75 to 90 minutes, stirring occasionally. Add a splash of water if it looks dry.

The ragù is ready when it is thick, rich and moist but not watery, with a little oil separating at the edges. Remove the bay leaves and taste for seasoning.

While the ragù cooks, melt the butter in a medium saucepan over a medium-low heat. Stir in the flour and cook for 2 minutes without letting it colour.

Add the milk a little at a time, whisking until smooth after each addition, before adding more. Bring to a gentle simmer and cook for 8 to 10 minutes, stirring, until it coats the back of a spoon. Season with the nutmeg, salt and pepper. If it has to wait, press a piece of baking parchment onto the surface to prevent a skin.

Heat the oven to 200°C (180°C fan, gas 6). Spread a thin layer of ragù over the base of a 30 x 20 cm baking dish and cover it with a single layer of pasta sheets, breaking them to fit.

Spoon over a layer of ragù, then a layer of béchamel, and sprinkle with a little grated Parmesan. Repeat, finishing with 4 layers of pasta in total.

Cover the top completely with the rest of the béchamel, right to the edges, so the pasta softens as it cooks and the corners do not turn hard. Scatter over the remaining Parmesan.

Bake on the middle shelf for 40 to 45 minutes, until the top is deep golden and the edges are bubbling. A knife slid into the centre should meet no resistance. If the top darkens too quickly, cover it loosely with foil.

Rest for 15 minutes before cutting so the layers set. Serve with a green salad.