Spread out the boned turkey breast on a work surface.

Soak the bread in the milk for 30 seconds. Squeeze out excess milk. Place the bread in a large bowl with the pork, veal, ham, salami, eggs, Parmesan cheese, basil, salt and pepper to taste, and hot pepper flakes. Mix well.

Stuff the turkey with this mixture and tie the opening in back securely with kitchen string. In a large heavy-bottomed pot heat 1 cup of olive oil. Add the onions and garlic, and cook for 5 minutes, stirring often. Stir in the tomato paste and add 1 cup of hot water. Stir in the bouillon cubes, rosemary, salt and pepper to taste, hot pepper flakes, and the sugar. Stir and cook until the bouillon cubes have dissolved. Add the stuffed turkey breast, breast side up. Cover the turkey with cool water. Sprinkle the surface of the water with the flour, cover and slowly bring to a boil. When a boil is reached, cook over low heat for 2 hours, turning occasionally.

Remove the turkey from the pan to a carving board.

Pass the sauce from the pan through a food mill. Serve it with the sliced turkey.