1) Mix greek yogurt, sour cream, lime and cilantro in a bowl. Sprinkle about a 1/2 tsp. of salt and pepper and mix that in as well. Set this bowl aside.
2) Heat olive oil in pan on medium heat.
3) Place chicken breasts in pan and sprinkle salt, pepper, cumin and chili pepper to your liking.
4) Cook on one side for 3-4 minutes, then flip. Let cook on this side for another 3-4 minutes. Turn down to low heat or a simmer, then cut chicken into small dices in the pan to make sure the chicken is fully cooked through.
4) In a new bowl, combine black beans, corn, red pepper, avocado, chicken and yogurt dressing and mix together.
5) Place chicken salad on top of lettuce leaf