preheat oven to 350. Bake pie shell according to package instructions. Peel the tomatoes and slice into ¼ inch slices. Lay slices out on a sheet tray over 3 layers of paper towels. Sprinkle the tomato slices with kosher salt and allow to drain for at least 30 minutes.
Over medium heat in a skillet, sauté the onions and garlic until they are soft. Remove from the heat and set aside.
When tomatoes appear to have lost most of their water (after more than30 minutes) , blot off the face up side of the tomatoes with paper towels to remove as much of the puddled water as possible (this keeps your pie from becoming soupy).
In a bowl, mix the cheese and the mayo together and set aside.
Mix the onion and garlic mixture together with the cheese and mayo mixture until well blended.
Place a layer of tomato slices into the bottom of your pie crust – and sprinkle this with pepper. Use about ¼ of the cheese/mayo mix to cover the tomatoes – no need to spread evenly or to try to spread out – just a few spoonfuls here and there will be fine. Cover with ½ of the basil
Place a second layer of tomatoes on top of the first layer, sprinkle with pepper and cover with the rest of the basil. Use the rest of the mayo/cheese mix to cover the tomato layer. Bake in the center of the oven for about 30-35 minutes until the cheese is golden and bubbly. Remove from the oven and allow to rest for 30 minutes before serving. Serve warm.