You will need:
1 pie crust
2 1/2 pounds tomatoes, thinly sliced
salt
1 onion, chopped
1 tablespoon
butter
1/2 cup basil, chopped
pepper
1/2 cup feta crumbled cheese
1/2 cup freshly grated Parmigiano-Reggiano cheese
1/4 cup mayonnaise
a handful of shredded mozzarella
Preheat oven to 425. Place pie crust in a 9-inch pie plate and bake for 20 minutes.
Place tomatoes in a single layer and sprinkle with 1 tsp. salt. Set aside. Sauté onion until caramelized. Layer tomatoes, onion, and basil in prepared crust. Season with a pinch of pepper. Stir together cheeses and mayonnaise and spread over pie. Top with mozzarella and bake at 350 for 30 minutes.