Preheat oven to 350 degrees F (175 degrees C). Lightly grease a 9x13 inch baking dish.
To Make Crust: In a medium bowl blend flour and butter or margarine until mixture resembles coarse crumbs. Add egg and blend just until dough begins to clump. Press dough onto the bottom of a lightly greased 9x13 inch baking dish (dough will be thin). Bake in the preheated oven for about 10 minutes, until lightly golden. Let cool and set aside (Note: Keep oven on at same heat.)
To Make Filling: Place tomatoes, reserved oil, garlic and oregano in a blender or food processor. Chop finely. Blend in eggs. Add cream cheese (should be room temperature) and blend all until smooth. Add sour cream and blend until all mixed together.
Transfer mixture to a medium bowl and stir in green onion. Season with salt and pepper to taste and pour filling into reserved crust. Bake in the preheated oven until filling puffs up and is light brown, about 20 minutes. Cool to room temperature and cut into squares. Serve.
