1 (9-inch) prebaked deep dish pie shell
3 tomatoes , peeled and sliced
1 small zucchini , sliced into rings
1 small yellow squash , sliced into rings
1/2 cup sliced sweet or red onion
10 fresh basil leaves , chopped
1 cup grated mozzarella
1 cup grated cheddar
3/4 cup mayonnaise (or half mayo, half Greek yogurt)
2 Tbsp fresh grated Parmesan Cheese
Salt and pepper
Preheat oven to 350 degrees F.
Place the tomatoes in a colander in the sink in 1 layer. Sprinkle with salt and allow to drain for 10 minutes. Use a paper towel to pat-dry the tomatoes and make sure most of the excess juice is out. (You don't want wet (juicy) tomatoes or your pie will turn out soggy).
Heat a large skillet over medium-high heat. Season zucchini and squash with salt and pepper. Saute the squash in a single layer for 2-3 minutes on each side or until golden brown. Remove to a paper towel.
Layer the tomato slices, zucchini, squash, and onion on the bottom of the pie shell. Sprinkle basil on top. Combine the grated cheeses and mayonnaise together. Smooth cheese mixture over the top and sprinkle parmesan cheese on top. Bake for about 30 minutes or until lightly browned. Allow to cool for at least 10 minutes.
To serve, cut into slices and serve warm.