1. Cook pasta according to package directions.
2. Meanwhile, stir together milk and flour.
3. Sauté the prosciutto and garlic in a non-stick pan. Add the milk to the mixture and snipped basil. Cook and stir over medium heat until mixture is bubbly and thickened. Cook and stir 1 minute more.
4. Add the thawed peas, prosciutto and 1/4 cup Parmesan cheese. Stir until the cheese is melted. Add the tomatoes and cook for 1 minute more. Top the pasta with sauce and sprinkle each serving with remaining cheese and ground pepper.