In a saucepan, brown the finely chopped onion in the oil, then add the tomato. When the sauce starts to boil add the salt and last the cooking for another 30 minutes at a very low flame. I brown the meat in a pan, then I pour the wine and let it evaporate. Prepare the filling by adding the ricotta cheese, diced mozzarella, cheese, a pinch of salt and pepper to the cooled meat. I heat the lumaconi, drain them al dente, cool them under running water and then fill them. I prepare a bowl with a layer of gravy and I place the snails one next to the other then season them with the remaining sauce and I cook in a preheated oven at 180 ° C for 15 minutes.