Whisk together the chili powder, cumin, paprika, oregano, salt, black pepper, and lime juice in a bowl. Toss the chicken strips in the mix until evenly coated. Quick marinade, big payoff.
Heat one tablespoon of olive oil in a large skillet over medium-high heat. Sear the chicken until golden and just cooked through, about 4–6 minutes. Remove to a plate and set aside.
In the same skillet, add the remaining tablespoon of olive oil. Toss in the onion and peppers. Sauté until they’re crisp-tender and blistered in spots, about 5–7 minutes.
Add the garlic and cook for another minute, until fragrant. Return the chicken to the pan and toss everything together until heated through and nicely mingled.
Taste and adjust seasoning with a pinch more salt or lime juice if you like a brighter kick. Serve hot with warm tortillas and your favorite toppings.