Preheat. Preheat the grill to 400 degrees F. Once the grill temperature is stabilized at 400 degrees, place a 12-inch cast iron skillet over the fire and allow it to preheat.
Season the chicken. Trim any excess fat from the chicken breasts, slice into strips, and season on all sides with 2 Tablespoons Fiesta Rub.
Prep chorizo and veggies. Remove the chorizo from its casing and seed the jalapeno and bell pepper. Chop the peppers and onion into slices, just be sure to cut them all the same size so they have the same cook time. Drizzle with 1 Tablespoon of the olive oil and season with remaining Fiesta Rub.
Cook chorizo and veggies. Pour about 2 Tablespoons of the oil in the skillet, followed by the chorizo. Break apart the chorizo while browning. After 2 minutes, add the sliced vegetables in with the chorizo, stirring often for even cooking and caramelization.
Grill the chicken. Once the veggies are on, it's time to grill the chicken. Depending on space, you can clear space for the chicken to nestle in over the hottest point of the skillet or lay the chicken strips directly on the hot grill grates. Either way, be sure to turn the chicken every couple of minutes to prevent burning. Place the chicken on the grill and cook for 4-6 minutes, or until the chicken reaches 165 F.
Mix all meat and veggies. Add the chicken to the skillet and toss the chicken, vegetables, and chorizo all together.
Assemble. Remove the skillet from the grill and dish up in corn or flour tortillas with your favorite fajita toppings.