First of all prepare the béchamel sauce: put the butter in a small, heavy-bottomed, pan over a low heat. As soon as it has melted, add the flour and stir for 2-3 minutes with a whisk, without letting the mixture brown. Bring the milk to the boil, pour a small amount into the saucepan and mix thoroughly; then gradually add the rest, stirring constantly. Cook for approximately 10 minutes, over a very low heat, stirring all the time so that the sauce doesn’t stick to the bottom of the pan. Turn the heat off and season with salt and nutmeg. Put the béchamel to one side, covering it with cling film to avoid a “skin” forming on the surface.

Clean the cauliflower, detach the florets and boil them in plenty of salted water, with 2 spoonfuls of vinegar (this helps to lessen the “smell” of the cauliflower while cooking). After about 15 minutes, to see if they are cooked, “test” a piece with the prongs of a fork; if they go in easily, strain the cauliflower and leave it to cool down (set aside the water, you’ll need it to cook the pasta). In a heavy-bottomed frying pan, sauté 1 clove of garlic with 3 spoonfuls of olive oil; when it has browned, remove it, tip in the cauliflower florets and sauté them for a few minutes. Again in a heavy-bottomed frying pan (you can use the same one used for the cauliflower, transferring it onto a plate and setting it aside), heat 3 spoonfuls of olive oil with 10 sage leaves and 1 clove of garlic; when the garlic begins to brown, remove it and add the squash, cut into small pieces. Season with salt and pepper, stir and cook for 10-15 minutes; if you see that it’s drying out too much, add a little of the water the cauliflower was boiled in. When the squash has become soft, add the cauliflower and stir well, then put everything through a food mill to obtain a purée.

Cook the rigatoni in the water the cauliflower was boiled in (which in the meanwhile you have brought back to the boil), strain them when very “al dente” and put them on one side. Distribute a few spoonfuls of béchamel sauce in the bottom of an oven dish. Use a teaspoon to fill the rigatoni with the squash and cauliflower purée, then arrange them in the dish, one beside the other, on top of the béchamel. When you’ve completed the first layer of rigatoni, cover them with more béchamel and half of the diced pecorino cheese. Then create another layer of rigatoni full of the purée, finish off with béchamel and the remaining diced pecorino. Sprinkle the crumbled bread over the surface, add the remaining sage leaves here and there, cover with kitchen foil and bake in a preheated oven, at 200 °C, for 20 minutes. Then remove the foil and bake for another 10 minutes; a delicious, crisp, golden crust will form on top!