Add the peppers to the same heated skillet (no need to wash skillet and drizzle with a little extra oil only if needed), and cook until soft and slightly charred. Season with salt and pepper.
While the chicken is cooking, prep the riced broccoli: combine the riced broccoli and minced garlic in a pot over high heat. Once the riced broccoli is cooked through, stir in 3 tablespoons (1 large) lime juice and 3 tablespoons packed & finely chopped cilantro. Season to taste with salt and pepper.
Place lettuce on the bottom of 6 bowls. Divide the riced broccoli, chicken, peppers, corn, black beans, onion and avocado evenly among the bowls.
Top each bowl with toppings of your choice and, if using, drizzle dressing evenly over the bowls.