In a bowl, toss the chicken strips with chili powder, cumin, smoked paprika, oregano, salt, and pepper until evenly coated.
Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add the chicken in a single layer, working in batches if needed. Cook for 5 to 7 minutes, turning once, until browned and the thickest strips reach 165°F. Transfer to a clean plate.
Add the remaining oil to the skillet. Cook the bell peppers and onion for 5 to 7 minutes, stirring occasionally, until tender-crisp and lightly charred at the edges.
Add the garlic and cook for 30 seconds. Return the chicken and any juices to the pan, add lime juice, and toss until hot. Remove from heat.
Warm the tortillas in a dry skillet or microwave wrapped in a damp towel. Serve the chicken and peppers with tortillas, salsa, avocado, cilantro, and lime wedges.