1. In a large pot of boiling salted water, cook fettuccine 8 to 10 minutes until al dente.
2. To prepare the sauce, in a bowl, whisk together eggs and Parmesan and set aside.
3. In a small saucepan, bring chicken stock to a boil, add peas and cook until tender and set aside.
4. In a large saucepan, melt butter over medium heat cook onions until golden.
5. Stir in pea mixture and prosciutto and cook for 1 minute.
6. Add drained pasta and egg mixture, toss and serve.