Prep the chicken: Pat the chicken dry with paper towels. In a bowl, toss it with 1 tbsp oil, half the salt and pepper, chili powder, cumin, smoked paprika, oregano, and red pepper flakes if using.
Add half the lime juice. Stir to coat and set aside while you prep the vegetables.
Heat the pan: Place a large skillet (12-inch) over medium-high heat. Let it get hot before adding anything.
This helps you get good color without overcooking.
Sear the chicken: Add the chicken in a single layer. Don’t overcrowd—cook in two batches if needed. Sear 3–4 minutes per side until browned and just cooked through.
Transfer to a plate and tent loosely with foil.
Cook the vegetables: Add the remaining 1 tbsp oil to the pan. Toss in the onions and peppers with the remaining salt and pepper. Cook 5–7 minutes, stirring occasionally, until crisp-tender with some char.
Add garlic in the last minute and stir until fragrant.
Deglaze (optional): If the pan has browned bits, splash in the broth or water. Scrape with a spatula to release all that flavor.
Combine and finish: Return chicken and any juices to the skillet. Toss everything together over medium heat for 1–2 minutes.
Turn off the heat and stir in the remaining lime juice. Taste and adjust salt, pepper, or heat.
Serve: Sprinkle with cilantro. Serve hot with tortillas and your favorite toppings, or build bowls over rice, cauliflower rice, or greens.