Lake ravioli

500 g all-purpose flour, 3 eggs, 1 tablespoon tomato paste, 1 glass of water

for the filling:

200 g lake fish bellies (the less substantial part of the fillet, usually discarded), 200 g diced celery, carrots and onions, 200 g leafy green vegetables (chard, spinach, herbs, ribs), 2 eggs, salt and pepper to taste

for the sauce:

200 g fish heads and bones, 1 bunch of mixed aromatic herbs, 2 garlic cloves, 1 bunch of parsley, 2 tablespoons flour, salt and pepper to taste

Arrange the flour in a well on a pastry board, add the egg and tomato paste and begin kneading, gradually adding the water until a soft and smooth dough is obtained. Form a ball, wrap it in plastic wrap and let it rest in a cool place for one hour. Meanwhile, prepare the filling by sautéing all the fish bellies and any filleting scraps in a pan together with the vegetables for the sauté and the leafy greens for a few minutes. Blend the mixture with two eggs, salt and pepper. Once a compact and homogeneous mixture is obtained, cover it and let it rest at room temperature. Take the dough again, roll it out into a thin sheet with a rolling pin and cut strips about 8 cm high. Place a teaspoon of filling every 6 cm along the lower part of the pasta strips and fold the upper part over, covering the filling with the pasta, pressing the edges well so they do not open during cooking. Cut the strips at equal distances with a sharp knife or with the appropriate wheel cutter to obtain square ravioli. Arrange on a floured surface and let rest. For the sauce: put the heads, fish bones, herbs, garlic, salt and pepper in a pot with plenty of cold water and cook for at least one hour, until a concentrated broth is obtained. Strain and place in a smaller pan and add two tablespoons of flour while constantly stirring, so as to thicken the sauce to taste. Plunge the ravioli into boiling water for 3 minutes and finish cooking in the pan with the sauce for another couple of minutes. Serve with a drizzle of raw extra virgin olive oil and a sprinkling of fresh parsley.