Avocado, diced tomatoes, and parsley or cilantro, for topping
In a large deep skillet or pot, add olive oil and place over medium-high heat. Season chicken thighs with salt and pepper then brown chicken on both sides. Using a pastry brush, brush a generous amount of BBQ sauce onto the chicken on both sides while it is browning. Remove chicken from skillet once halfway cooked through, about 3-4 minutes. Set aside on a plate.
In the same skillet, add onion and garlic. Cook until softened then add corn and black beans. Toss to incorporate. Add the rice to the skillet and gently "toast" it for a couple minutes.
Carefully pour the chicken stock in the skillet and add the remaining BBQ sauce into the skillet. Stir to incorporate completely. Season with salt and pepper.
Bring to a boil and then reduce to a medium-low heat. Place chicken back into skillet and nestled into the rice and liquid. Cook covered for 30 minutes, or until rice is completely cooked through.
Add cheese on top and cover skillet to melt. Once cheese has melted, remove skillet from heat and top with avocado, diced tomato, and parsley or cilantro, if desired.