Vegetable lasagne

Method

1. Finely chop the onion and the garlic cloves and cut the courgette, carrot and mushrooms into small dice, all the same size. Heat the olive oil in a wide pan and soften the onion and garlic over medium heat for 5 minutes, until the onion turns translucent without colouring.
2. Add the carrot and courgette and let them sweat for 5 minutes, stirring; add the mushrooms and sauté for a further 5 minutes over higher heat, until they release their water and it evaporates.
3. Add the diced tomato and the tomato pulp, season with salt and pepper and let it reduce for 10 minutes over low heat, until the sauce is thick with no loose liquid in the bottom — a watery sauce turns the sheets to mush.
4. Béchamel: melt the butter in a pan, add the flour all at once and stir for 2 minutes over low heat, until you have a smooth paste that smells of biscuit. Pour in the warm milk a little at a time, whisking after each addition so no lumps form, and cook for 5 to 6 minutes until it thickens and coats the back of a spoon. Season with salt and pepper.
5. Spread two spoonfuls of the vegetable sauce over the base of the dish and alternate layers of lasagne sheets, vegetable sauce and béchamel, finishing with béchamel. The sheets must stay covered in sauce: that is the water they cook in.
6. Scatter over the grated cheese and bake in a preheated oven at 190 °C for 35 minutes, until golden on top and bubbling at the edges. Let it rest for 10 minutes before cutting.