Slice tomatoes and lay sliced on plates. Sprinkle lightly with salt and let sit at least 7-14 minutes, and up to 25 minutes.
Melt butter in small skillet over medium-high heat. Add onion and garlic and saute’ until onions are soft (about 6 minutes). Transfer to a medium-sized bowl.
- Drain water off of plates with tomatoes, With a paper towel, Gently blot tomatoes to soak up excess moisture.
Add cheese, eggs, herbs, and pepper to bowl. Stir to combine.
Arrange tomatoes in a single layer on a greased pie pan. Top with about 1/3 cup of the cheese mixture. Repeat until all ingredients have been used, finishing with a layer of tomatoes. Top this layer with a sprinkle of mozzarella cheese.
Bake at 360 degrees for 35-40 minutes, or until edges are lightly browned.
Allow to sit 4-5 minutes before serving.