Slice the chicken and veggies. Cut chicken into thin strips, about 1/2 inch wide. Slice peppers and onion into similar widths so everything cooks evenly.

Mix the seasoning. In a small bowl, combine chili powder, smoked paprika, cumin, garlic powder, onion powder, oregano, cayenne (if using), salt, and pepper.

Marinate quickly. In a large bowl, toss chicken with 1.5 tablespoons of oil, half the seasoning, lime zest, and half of the lime juice. Let it sit while you heat your skillet or oven.

Choose your cooking method. Skillet: Heat a large cast-iron or stainless skillet over medium-high. Add 1 tablespoon oil, then the chicken. Cook 4–6 minutes, stirring occasionally, until browned and cooked through. Remove to a plate.

Sheet pan: Preheat oven to 425°F (220°C). Spread chicken on a parchment-lined sheet pan. Roast 10–12 minutes until just cooked.

Cook the veggies. Skillet: Add remaining 1/2 tablespoon oil to the hot pan. Add peppers and onions with the remaining seasoning. Cook 4–6 minutes until crisp-tender with slight char.

Sheet pan: Add peppers and onions to the pan, drizzle with remaining oil, sprinkle the rest of the seasoning, and roast 10–12 minutes until tender.

Combine and finish. Return chicken to the pan (or toss together on the sheet pan). Squeeze the remaining lime juice over the top. Adjust salt and pepper. Sprinkle with chopped cilantro.

Assemble meal prep boxes. Divide cauliflower rice among 4–5 containers. Top with fajita chicken and veggies. Add optional toppings in separate compartments or small containers.