Preheat the oven to 350℉.
Lay out a few sheets of paper towels on the countertop and lay the sliced tomatoes, in a single layer, on top of the paper towels. Then, using additional paper towels, gently pat dry the tops of the tomatoes. Sprinkle the salt on the tomatoes and let them rest on the paper towels for 40 minutes to extract excess moisture. Pat the tomatoes dry once more to remove any remaining excess liquid.
3 large tomatoes, 1½ teaspoons kosher salt
Prick the bottom of the thawed pie crust with a fork in several spots. Pre-bake the pie crust for 10 minutes in the oven.
1 (9-inch) frozen deep-dish pie crust
In a medium bowl, stir together the mayonnaise, shredded cheddar cheese, garlic powder, and black pepper until well combined. Set aside.
1 cup full-fat mayonnaise, 1 cup shredded cheddar cheese, 1 teaspoon garlic powder, 1 teaspoon black pepper
Sprinkle the shredded mozzarella cheese on the bottom of the baked pie crust. Layer half of the sliced tomatoes, then add the sliced basil leaves and green onions, followed by the remaining tomato slices. Evenly spread the mayonnaise cheese mixture over top.
1/2 cup shredded mozzarella cheese, 10 fresh basil leaves, 1 green onion
Bake for 30-35 minutes or until golden brown.
Remove the tomato pie from the oven and allow it to rest for 15 minutes, on a wire cooling rack, before slicing and serving. Enjoy warm or closer to room temperature!