In a large Mixing Bowl, whisk together 2 tablespoons of the 3 tbsp olive oil divided, 3 tbsp lime juice freshly squeezed (about 2 limes), 3 cloves garlic minced minced, 1 ½ tsp chili powder, 1 tsp ground cumin, 1 tsp smoked paprika smoked, ½ tsp dried oregano, ½ tsp salt, and ¼ tsp black pepper freshly ground until well combined.

Add the sliced 1 ½ lb boneless skinless chicken breasts sliced into ¼-inch strips against the grain to the Mixing Bowl and toss well to coat every piece. Cover and let marinate at room temperature for at least 30 minutes, or refrigerate for up to 4 hours for deeper flavor.

Heat a large Cast Iron Skillet over high heat until very hot — about 2 minutes. Add 1 tablespoon of 3 tbsp olive oil divided and swirl to coat. Add the sliced 1 large yellow onion halved and sliced into thin half-moons and 1 red bell pepper seeded and sliced into thin strips, 1 yellow bell pepper seeded and sliced into thin strips, 1 green bell pepper seeded and sliced into thin strips, season with ½ tsp ½ tsp salt, and cook undisturbed for 2 minutes to get some char, then stir and cook another 3–4 minutes until softened with lightly charred edges. Transfer to a plate and set aside.

Return the Cast Iron Skillet to high heat. Add the remaining 1 tablespoon of 3 tbsp olive oil divided. Remove the 1 ½ lb boneless skinless chicken breasts sliced into ¼-inch strips against the grain from the marinade (letting excess drip off) and add it to the skillet in a single layer. Cook undisturbed for 3 minutes until a golden sear forms on the bottom.

Flip the 1 ½ lb boneless skinless chicken breasts sliced into ¼-inch strips against the grain and cook for another 2–3 minutes until cooked through (internal temperature of 165°F). Avoid overcrowding — cook in two batches if needed to maintain a proper sear.

Return the cooked 1 red bell pepper seeded and sliced into thin strips, 1 yellow bell pepper seeded and sliced into thin strips, 1 green bell pepper seeded and sliced into thin strips, and 1 large yellow onion halved and sliced into thin half-moons to the Cast Iron Skillet with the 1 ½ lb boneless skinless chicken breasts sliced into ¼-inch strips against the grain. Toss everything together over high heat for 1 minute so the flavors meld. Taste and adjust seasoning with ½ tsp salt, ¼ tsp black pepper freshly ground, or an extra squeeze of 3 tbsp lime juice freshly squeezed (about 2 limes).

Warm the 8 piece flour tortillas medium (8-inch), warmed: wrap them in a damp paper towel and Microwave for 30–45 seconds, or heat them one at a time directly over a gas burner or in a dry Skillet for 20–30 seconds per side until lightly charred and pliable. Wrap in Aluminum Foil to keep warm.

Serve the sizzling 1 ½ lb boneless skinless chicken breasts sliced into ¼-inch strips against the grain and vegetable mixture straight from the Cast Iron Skillet alongside the warm 8 piece flour tortillas medium (8-inch), warmed and all your toppings: 1 cup sour cream, guacamole, salsa, 1 cup shredded Mexican cheese blend, fresh ¼ cup fresh cilantro roughly chopped, and 3 tbsp lime juice freshly squeezed (about 2 limes) wedges. Let everyone build their own fajitas at the table.