This recipe, created by Lila Y. Cornelio, won Best Entrée in VT's 2011 Chefs' Challenge. After going veg at age 15, Cornelio began making meatless versions of her family's Mexican recipes. For her athletic performance cuisine class, she fed a wrestling team this tortilla casserole, based on a chicken dish her grandmother used to make. Her aim: keep it nutritious but just as flavorful. "Instead of frying tortillas, I baked them, which eliminated hundreds of calories alone," she says.
1. Preheat oven to 350°F. Line 2 baking sheets with parchment paper. Spread tortilla strips in single layer on baking sheets. Spray with cooking spray, flip, and spray other side. Bake 7 to 10 minutes, turning once, or until crispy. Cool.
2. Place 4 tomatoes, 6 tomatillos, 3/4 cup onion, 1 jalapeño, 3 cloves garlic, oregano, peppercorns, thyme, and bay leaf in large pot; cover with 3 cups water. Bring to a boil over medium-high heat, and simmer 15 minutes, or until tomatoes are soft and tomatillos are pale. Remove bay leaf; remove pot from heat.
3. Preheat oven to broil. Spread remaining 4 tomatoes, 6 tomatillos, 3/4 cup onion, jalapeño, and 3 cloves garlic on baking sheet. Broil 25 minutes, or until vegetables are browned, turning occasionally. Cool slightly.
4. Adjust oven temperature to 375°F. Transfer broiled vegetables to pot with boiled vegetables, and stir in cilantro. Blend in batches in blender until smooth. (You should have about 9 cups.)
5. Coat 13- x 9-inch baking dish with cooking spray. Wipe out pot, and heat over medium heat. Slowly add sauce to pot (sauce will sizzle). Cover, reduce heat to medium-low, and simmer 15 minutes, or until sauce is slightly thickened.
6. Increase heat to medium-high. When sauce boils, stir in egg whites 5 seconds, or until they feather into sauce. Add half of queso fresco, mozzarella, and tortilla strips. Toss gently to coat tortilla strips.
7. Spread in prepared baking dish. Cover with foil, and bake 10 minutes, or until tortillas have absorbed most of sauce. Let stand 6 minutes. Serve topped with lettuce, sour cream, sliced avocado, and remaining queso fresco.