Reduce oven to 400 degrees. Lightly butter an approximately 10-inch tart or pie pan. In a bowl, whisk egg until frothy. Whisk in milk and oil. In another bowl, combine cornmeal, cheddar, parmesan, sugar and salt. Stir into egg mixture until well blended. Press crust mixture over bottom and halfway up the sides of pan. Bake for approximately 15 minutes or until lightly golden brown. (If crust bubbles during cooking process, poke down with fork or skewer. You may have to do several times.) To Assemble: Sprinkle ½ cup cheddar cheese over crust. Pour half of the vegetables over top. Sprinkle another ½ cup cheddar cheese over vegetables. Pour in remaining vegetables and finish with ½ cup cheddar cheese and two tablespoons of parmesan. Slice the tomato slices in half and place them in scallop design around the edges of the tart. Bake at 400 degrees for about 25 minutes or until cheese is melted and golden on top.