In a large pan, sauté all the finely chopped vegetables with 4 tablespoons of oil.

Stir frequently with a wooden spoon for about 10 minutes over low heat, then add the minced meat, raise the flame a little and brown. After about 20 minutes, add the tomato sauce, salt, pepper and a teaspoon of chilli pepper paste.

Continue cooking very gently and in the meantime prepare the polenta. Bring two liters of water to the boil, drawn off the heat and, with the aid of a wooden spoon or, even better, of a whisk, shower in the cornmeal flour, stirring continuously so that the lumps do not form.

Return to very low heat for about 40 minutes and, meanwhile, prepare the bechamel sauce. Finish cooking the polenta, turn it out onto a pastry board (make sure that it is no thicker than ½ inch) and allow to cool, while the meat sauce is simmering away. Cut into squares and arrange a layer in a large, buttered ovenproof dish. Alternate a layer of polenta with 5 tablespoon of ragu and a handful of Parmesan cheese.

Continue in this way until the dish is full. Spread a generous ladle of bechamel sauce between the layers and on the top, then bake a medium oven for half an hour, until a nice golden crust form on top.