Set a large pot of water with a pasta insert over high heat and bring to a boil. Place the pasta in the water and return to a boil, being sure to stir the pasta until the water boils again.
While the pasta cooks, set a large 12-inch saute pan over medium high heat, and add the olive oil and the butter. Once the butter has melted, add the onions to the pan and saute until translucent, about 3 minutes. Add the garlic to the pan and saute for 30 seconds. Place the prosciutto in the pan and saute for 1 minute. Deglaze the pan with wine and cook until it is nearly evaporated, about 30 seconds. Add the cream, peas, salt and pepper to the pan and let the cream reduce by half, 4 to 5 minutes. If the pasta is not yet cooked, turn the fire off the sauce while the pasta continues to cook.
Strain the pasta from the water once it is cooked, and place in a large heat resistant bowl. Pour the sauce over the pasta and sprinkle with the cheese and the parsley. Use tongs are two large forks to stir the sauce into the pasta and serve while hot.