Put a pot full of water on the stove. Then brown the onion in a bit of oil and pour the peas. Let them cook stewing with a ladle of cooking water and for about 15 minutes on high heat. When the peas are cooked, lower the heat and add Pancetta cut into small pieces. Meanwhile cook the pasta. Drain it and put it in the pan together with peas and Pancetta and finally add the cream. Serve still warm.