A friend of mine brought this pie to lunch one day, saying that she had just thrown in some vegetables that she had on hand. That’s the great thing about this dish—you can vary the ingredients based on what you like or what you have in your garden or refrigerator! I recently rediscovered the recipe when we had an overabundance of yellow squash and zucchini, and it quickly became a summer specialty in my family.
Heat the olive oil in a medium skillet over medium heat. When hot, add the garlic and sauté for 2 minutes; don’t let it brown. Add the onion, zucchini squash, yellow squash, and half of the salt and pepper. Cook until the squash is tender, about 15 minutes. Divide the mixture in half.
Mix the mayonnaise and cheeses and set aside. Layer the sliced tomatoes in the bottom of the baked pie crusts. Sprinkle the tomatoes with the remaining salt and pepper. Layer the squash mixture on top of the tomatoes, then layer the water chestnuts. Top each pie with half of the mayonnaise and cheese mixture. Bake, uncovered, for 40 minutes. Allow the dish to stand for 15 minutes before cutting into wedges and serving.