Whisk first seven ingredients for marinade together. Pour half the marinade into a shallow dish to marinate chicken for 2 hours. Refrigerate reserved untouched marinade to use as a dressing. Heat 1 teaspoon oil in skillet over medium heat and grill fillets on each side until golden, crispy and cooked through. Fry peppers and onion in skillet. Slice chicken into strips. Prepare salad with lettuce, avocado slices, peppers, onion and chicken, Drizzle with remaining dressing. Serve with sour cream.