Heat oven to 375°F. Cook pancetta in wide saucepan over medium 6 to 8 minutes until lightly crisp. Leave 1 tablespoon fat; spoon off rest.
Cook shallot 2 minutes; stir garlic 30 seconds. Add tomatoes, cream, water, and pepper; gently simmer 5 minutes.
Boil tortellini with tablespoon salt just 1 minute; gently drain. Fold into sauce with frozen peas.
Transfer to deep 9-by-13-inch dish; top with mozzarella and Parmesan. Foil-cover; bake 20 minutes.
Uncover; bake 8 to 10 minutes until central tortellino filling and surrounding sauce reach 165°F. Rest 5 minutes.