Fit pie crust into a 9" pie plate; fold edges under and crimp. Line pie crust with aluminum foil and fill with pie weights or dried beans. Bake at 350° for 5 minutes; remove foil and weights and bake 4-5 minutes more.
Arrange tomato slices in pie crust, sprinkling each layer with sugar, salt and pepper. Sprinkle top layer evenly with flour.
Stir together mayonnaise and cheese; spread evenly over tomato. Bake at 350° for 30 minutes.
