Preheat oven to 375 degrees. Whisk together cheeses, eggs, s&p. In a cup, dissolve the cornstarch in milk then whisk it into the cheese mixture and add basil. Pour into 9" glass pie plate. Arrange tomatoes on top, overlapping if necessary. Sprinkle tomatoes with more s&p. Bake 30-35 minutes until lightly browned around the edges and center is puffed.