Step 1

Preheat oven to 350 degrees F.

Step 2

Place the tomatoes in a colander in the sink in 1 layer. Sprinkle with salt and allow to drain for 10 minutes. 

Step 3

Use a paper towel to pat-dry the tomatoes and make sure most of the excess juice is out. (You don't want very wet tomatoes or your pie will turn out soggy).

Step 4

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

Step 5

Layer the zucchini, squash, tomato slices, and onion on the bottom of the pie shell. (Make sure pie shell is pre-baked, and completely cool, to avoid sogginess). Sprinkle basil on top. 

Step 6

Combine the grated cheeses and mayonnaise together. Smooth cheese mixture over the top and sprinkle parmesan cheese on top. 

Step 7

Bake for about 30 minutes or until lightly browned. Allow to cool for at least 15 minutes.

Step 8

To serve, cut into slices and serve warm.