Mix olive oil, garlic powder, smoked paprika, salt, and pepper in a small bowl. Rub this mixture evenly over the chicken breast and let it marinate for about 10 minutes.
Heat a grill pan or skillet over medium-high heat. Cook the marinated chicken for about 6–7 minutes per side until it reaches an internal temperature of 165°F (74°C). Let it rest for about 5 minutes before slicing it into strips.
Cook your brown rice or quinoa according to package directions. Prep your veggies by halving cherry tomatoes, dicing red onion, shredding lettuce or spinach, rinsing black beans, and heating corn if it's frozen.
In each serving bowl, add your cooked grains as the base. Artfully arrange corn kernels, black beans, cherry tomatoes, diced onion, greens, and sliced chicken on top.
Mix together light ranch dressing and BBQ sauce until well combined. Drizzle this mixture over each assembled bowl and sprinkle shredded cheddar cheese on top. Garnish with fresh cilantro or green onions if desired.