Preheat oven to 350F. Remove pie shells from wrapping. Use one as bottom crust on a cookie sheet or pizza pan. Wet finger tips to make a 1/2 inch edging around crust. In a 4-quart pan, boil water. Add 1 teaspoon salt and shrimp. Boil 2 minutes. Remove shrimp and drain well. Arrange shrimp on bottom crust, single layer. Mix beaten eggs with grated cheese and 1/2 teaspoon salt. Spread on crust. Saute onions and peppers in butter for about 3 minutes in microwave oven. Spread this mixture over shrimp. Cut 1/4- off tog crust, place over mixture. Pinch crusts together. Cut vents in desired pattern. Whisk egg whites and cornstarch until foamy. Brush top crust with this mixture. Bake at 350F for 30 minutes, until golden brown. After baking let set 5 minutes. Using a large spatula, loosen crust from pan and slide onto serving platter.
Cajun Country -- New Iberia, Louisiana