1. Preheat oven to 350º. Prepare Sour Cream Pastry.
2. Meanwhile, place tomatoes in a single layer on paper towels; sprinkle with salt. Let stand 30 minutes. Pat dry with paper towels. Stir together next 3 ingredients and 3/4 cup of cheese.
3. Roll Sour Cream Pastry into a 13-inch circle on a lightly floured surface. Fit into a 9-inch pie plate; fold edges under, and crimp.
4. Bake at 350° for 10 to 12 minutes or until lightly brown. Remove from oven, and sprinkle remaining 1/4 cup cheese over bottom of crust. Arrange tomato slices over cheese in crust; spread mayonnaise mixture over tomatoes.
5. Bake at 350º for 34 to 37 minutes. Let cool 5 minutes before serving.