While the pie crust chills, prepare the tomatoes and pie filling: Wash and dry the large tomatoes. Slice thinly and spread tomatoes on a paper towel or in a colander. Sprinkle with a teaspoon of salt and let tomatoes sit for about 20 minutes to drain.
Pre-heat the oven to 375 degrees.
Chop fresh basil into small pieces and set aside. In a small bowl, mix together 1/2 cup of cheddar cheese with 1/2 cup mozzarella cheese. Set aside.
Mix together the Creamy Tomato Pie Topping: 1/4 cup Greek Yogurt, 3 Tablespoons mayonnaise, 1/2 cup cheddar cheese, 1/2 cup mozzarella cheese, chopped chives (or green onion), salt, garlic powder, ground pepper and oregano.
Remove the pie crust from the refrigerator. Roll out on a floured surface and transfer into a 9 inch pie plate. Crimp the edges and prick the bottom of the pie crust with a fork. Pre-bake the pie crust for 10 minutes at 375 degrees.
While the crust is pre-baking, pat the tomatoes with paper towel and soak up all the excess juices from the tomatoes. The more you drain the tomatoes, the less "juicy" and soggy the pie will be.
After 10 minutes, remove the pie pan from the oven and spread the reserved cheddar/mozzarella cheese over the bottom of the pan. Next, layer the tomatoes around the pie, sprinkling with fresh basil as you go. Overlap the tomatoes until you've used all of the tomato slices.
Spread the creamy topping on top of the tomatoes, covering the entire pie. Bake for 30 minutes at 375 degrees Fahrenheit.
Allow the pie to cool before cutting and serving. If the tomatoes are especially juicy when you cut into the pie, soak up some of the juice with a paper towel so it doesn't get the crust soggy. Enjoy a slice of summer on a plate!