Split the pita breads in half so that you have 4 round pieces. Spread mayonnaise on one half of each one, and tahini on the other half. Place tomato slices onto the mayonnaise halves, and sprinkle with a pinch of salt. Place 2 slices of tofu onto the tahini halves, and sprinkle a few drops of soy sauce over. Place the open sandwiches on a large baking sheet.
Broil in the preheated oven until hot and bread is slightly toasted, about 4 minutes. Close the halves of each sandwich together, and cut into wedges to serve.