Line a baking sheet/s with a triple layer of paper towels and place the tomatoes on top in a single layer. Sprinkle with salt and let sit for 15 minutes. This will draw out the juices to help avoid a soggy pie. Cover with more paper towels and pat gently.

Toss the basil and green onions together in a small bowl. In a separate bowl, mix the Dijon mustard, mayonnaise, the three cheeses, red pepper, and black pepper.

Spread 1/2 of the cheese mixture in the bottom of the blind-baked cooled pie crust, add a layer of sliced tomatoes, and sprinkle with the basil and onion mixture. Gently spread the remaining cheese mixture on and then arrange another layer of tomatoes, Finish by sprinkling the rest of the basil and onion mixture on.

Bake for 35 to 40 minutes. Remove from the oven and let cool for 15 minutes before serving.