Slice tomatoes 1/4 inch thick and remove most of the seeds. Salt liberally and rest for 30 minutes on a wire rack lined with paper towels to remove excess moisture.
While tomatoes are drying out, pre-bake pie crust according to package directions.
Mix mayo, garlic, lemon juice and cheddar cheese together.
Sprinkle Parmesan cheese into bottom of baked pie crust.
Blot tomatoes dry with a paper towel and layer into pie crust, seasoning with pepper to taste between each layer.
Thinly slice onion and add a layer on top of tomatoes.
Chop basil and sprinkle on top of onions.
Spread mayo mixture on top and bake for 30-40 minutes or until golden brown.
Rest for at least 10 minutes before serving