Boil up plenty of salted water for the pasta. Cut the sausage into slices and fry in hot oil for about 5 minutes. Clean and wash spring onions and cut into rings. Peel garlic and chop finely.
Take out the sausage. Sauté spring onions and garlic in the frying fat for about 2 minutes. Dust with flour and sauté briefly. Deglaze with wine, tomatoes and juice. Bring everything to the boil and let it boil down for about 8 minutes.
Season to taste with salt, pepper and sugar.
Cook the pasta in boiling water according to the instructions on the packet. Drain, drain and put back into the pot. Fold in sausage and sauce. Serve everything. Spread the ricotta on top.