1. Prepare the Chicken and Vegetables: Begin by slicing the boneless, skinless chicken breasts into thin strips, about 1/2-inch thick. Next, core and slice the bell peppers and onion into similar-sized strips. Aim for uniform pieces so everything cooks evenly on the grill.

2. Season the Fajita Mix: In a large bowl, combine the sliced chicken, bell peppers, and onion. Drizzle with olive oil, then sprinkle generously with fajita seasoning, chili powder, ground cumin, garlic powder, salt, and black pepper. Toss everything together thoroughly until the chicken and vegetables are well coated with the spices. You should see a vibrant coating of seasoning on all the ingredients.

3. Preheat Your Grill: Preheat your outdoor grill or indoor grill pan to medium-high heat. Ensure the grates are clean and lightly oiled to prevent sticking. You’ll know it’s ready when you can hold your hand about 5 inches above the grates for only 3-4 seconds.

4. Grill the Chicken and Vegetables: Place the seasoned chicken and vegetables directly on the hot grill. Cook in batches if necessary to avoid overcrowding, which can steam rather than grill the ingredients. Grill for 5-7 minutes per side, or until the chicken is cooked through with no pink remaining (internal temperature should reach 165 F) and the vegetables are tender-crisp with nice char marks.

5. Assemble Your Bowls: While the chicken and vegetables are grilling, prepare your bowls. Divide the cooked brown rice and black beans evenly among your serving bowls. Add a scoop of corn kernels to each bowl.

6. Finish and Serve: Once the chicken and vegetables are perfectly grilled, remove them from the heat and divide them among the prepared bowls, placing them over the rice, beans, and corn. Garnish each bowl generously with fresh chopped cilantro and serve immediately with lime wedges for squeezing. Offer optional toppings like salsa, guacamole, or a dollop of plain Greek yogurt for an extra burst of flavor and creaminess.