Southern Tomato Pie

Bahan-bahan (6 porsi)

• 1 nine-inch (23-cm) frozen or homemade pie crust (not deep-dish) ()
• 2 lbs tomatoes, cored, seeded, and cut into ¾-inch (2-cm) pieces (I use vine-ripened)
• 1 large yellow onion, thinly sliced
• 2 tablespoons extra-virgin olive oil
• 1¼ teaspoons salt
• 1/4 teaspoon freshly ground black pepper
• 3/4 teaspoon sugar
• 1½ teaspoons fresh thyme leaves (or ½ teaspoon dried thyme)
• 2 tablespoons chopped fresh basil
• 1/2 cup mayonnaise
• 1 cup shredded fontina cheese (mozzarella can be substituted), divided
• 1/3 cup grated Pecorino Romano (Parmigiano-Reggiano can be substituted)