In a skillet, heat the olive oil over medium heat. Add the shredded chicken, chili powder, cumin, garlic powder, salt, and pepper. Stir to combine and cook for about 5 minutes until heated through. Remove from heat.
In a large bowl, combine the mixed salad greens, cherry tomatoes, black beans, corn, and diced avocado. Toss gently to mix.
Divide the salad mixture evenly among four bowls.
Top each bowl with the seasoned chicken, shredded cheddar cheese, salsa, and sour cream.
Garnish with fresh cilantro if desired and serve with tortilla chips on the side.