Mix together lime juice, chile powder, cumin and salt. Set aside 2 tablespoons of the mixture; place remainder in a resealable plastic bag and add the orange juice.
Add turkey to marinade in bag. Marinate in refrigerator for 2 hours.
Heat 1 tablespoon oil in a large nonstick skillet over medium-high heat. Remove turkey from marinade and add to skillet. Discard marinade. Cook 4 minutes, turning halfway through cooking time. Remove to a plate and cover with foil to keep warm.
Add remaining tablespoon oil to skillet. Stir in onion, green peppers, carrots and garlic. Cook, uncovered, 5 minutes, stirring occasionally. Add zucchini and mushrooms and cook an additional 5 minutes, stirring. Stir in turkey, reserved 2 tablespoons marinade and the salt; cook 1 minute.
Serve turkey and vegetables with cilantro, cheese, scallions and tortillas. If desired, accompany with Easy Avocado & Tomato Salsa (recipe, below).
Mix together plum tomatoes, red onion, 2 tablespoons chopped cilantro, olive oil, lime juice and salt. Dice the flesh of avocado and gently fold in. For a zestier salsa, add a finely chopped jalapeño.