1In a large skillet, cook turkey over medium heat until no longer pink; drain.
Add the onion, green pepper, and garlic. Cook and stir for 3 minutes. Stir in mushrooms; cook 1 minute longer. Stir in the beans, salsa, chilies, chili powder, cumin, salt, and hot pepper sauce.
Cook for 5 minutes.
Stir in cheese and corn; heat through.
2Spread about 1/3 cup filling on each tostada shell.
Sprinkle with the lettuce, tomatoes, and cilantro.