Fettuccine alla papalina

• 1 white onion
• 3½ ounces (100 g) sliced prosciutto

Finely chop the onion and cut the prosciutto into narrow strips. Put the onion and prosciutto in a deep skillet with half the butter and sauté over medium heat for about 4 minutes, or until golden brown. Meanwhile, break the eggs into a food processor, add 2 tablespoons of the parmigiano, the cream,