Ingredients: (for 4 people)For the dough: 400gr flour4 eggs2 dessert spoons extra virgin olive oilFor the filling:500gr boiled potatoes50 gr bacon1 egg50 gr parmesan cheeseSalt, pepper and nutmegFor the sauce:4 small onions50 gr pecorino (sheep's cheese)2 dessert spoons extra virgin olive oilCreate a mountain of flour, making a hole in the center, where you will put the eggs and extra virgin olive oil. Mix together and kneed for about 20 minutes, until the dough is elasticated. Stretch the dough and cut into circles 10 cm wide. In the meantime prepare the filling. Boil and strain the potatoes, then add the minced bacon, eggs and parmesan cheese, season with the salt, pepper and nutmeg. Now add a piece of the filling to the middle of each circle of dough and seal by hand to obtain the half-moon shape of the tortelli. Then add the tortelli to a full saucepan of boiling salted water. While this is boiling, gently fry a fresh onion for 2 minutes, adding the pecorino cheese until it has melted . Drain the tortelli once they have risen to the top of the pan (a few minutes) and quickly add to the pan with the onion and cheese, frying together for 1 minute. Serve immediately (don't wait for any latecomers!)