Preheat oven to 400°F and line a baking sheet with parchment paper.
Slice 1 pound tomatoes 1/4-inch thick and lay them on a double layer of paper towels. Sprinkle them liberally with salt and let them stand for 20 minutes, while you assemble the rest of the galette.
Lay pie crust on top of the parchment-lined baking sheet. Spread 1/4 mayonnaise over the pie crust, leaving a 1-inch border. Sprinkle the mayonnaise with 1/4 teaspoon kosher salt, 1/4 teaspoon garlic powder, and 1/8 teaspoon lemon pepper. Sprinkle 1 cup shredded Cheddar cheese over top.
Pat the tops of the tomatoes with paper towels until you’ve gotten out as much moisture as possible. Starting in the center, layer the tomatoes in a circular pattern over the cheese, leaving a 1-inch border.
Crimp the pie crust over the tomatoes. If the pie crust rips or doesn’t fit perfectly, no worries! Just pinch it back together and scooch the tomatoes around to make it work. Sprinkle the remaining 1/4 cup shredded Cheddar cheese over the tomatoes.
Using your fingers, spread 1 tablespoon mayonnaise over the exposed pie crust. Sprinkle the crust with 2 to 3 teaspoons Everything But The Bagel Seasoning (the mayo will make it stick).
Bake for 45 to 55 minutes, until the exposed pie crust is light brown and cooked through. Season the tomatoes with salt and pepper.
Wait 5 minutes before slicing to allow the galette to firm up. Sprinkle with 3 tablespoons fresh thinly sliced basil.
Enjoy hot, or at room temperature.
Store wrapped in plastic wrap in the refrigerator.