In a pot, sauté the onion and add the rooster. Turn it to brown on all sides and retain its juices, then deglaze with the wine. Add salt, black and red pepper, grated tomato, and water, and let it simmer, adding more water if needed. In the remaining broth (about 1 liter), add the pasta and let it cook for 15-20 minutes, stirring at first and then letting it thicken.