Unroll pie crust on cookie sheet. Spread ricotta mixture over center of crust to within 1 1/4 inches of edge of crust. Top with tomatoes, cut-side up, and 1/4 cup of the Parmesan cheese. Fold 1 1/4-inch edge of crust over filling, pleating crust as necessary. Brush egg mixture over crust edge, and sprinkle with remaining 4 teaspoons Parmesan cheese. Bake 30 to 35 minutes or until crust is golden brown. Cool 15 minutes.