In a skillet, heat the olive oil over medium heat. Add the black beans, corn, and diced tomatoes. Stir in the taco seasoning, and cook for about 5 minutes, or until heated through.
In a large mixing bowl, combine the cooked brown rice, sautéed bean and corn mixture, and shredded lettuce.
Divide the mixture into serving bowls.
Top each bowl with diced red onion, shredded cheddar cheese, Greek yogurt (or sour cream), and cilantro.
Season with salt and pepper to taste.
Serve your Taco Bell Power Bowls hot and enjoy!