Preheat oven to 375°F.
Arrange tomato slices on paper towels. Sprinkle with salt and let sit for 15 minutes. Pat dry.
Par-bake pie crust for 10 minutes and let cool slightly.
Layer tomatoes in the crust. Top with basil, green onions, and garlic.
In a bowl, mix mozzarella, cheddar, mayo, and pepper. Spread over tomato layer.
Bake for 30–35 minutes, or until golden and bubbly.
Let cool for 10 minutes before slicing.