Place the chicken breast halves between 2 pieces of plastic wrap or parchment and lightly pound to even thickness. Season both sides with ¼ teaspoon salt and pepper.
Heat large non-stick skillet over medium high heat. Spray with olive oil spray, add chicken breasts and brown each side, 2 minutes each. Remove chicken from pan and set aside on a plate.
Reduce heat to medium, add oil and onions and sauté, scraping brown bits with a wooden spoon, about 3 minutes or until onions are tender. Add garlic and sauté 30 seconds more. Add tomato sauce, chicken broth, ½ teaspoon salt, cumin, chipotle pepper and adobo sauce, stir and bring to a boil. Reduce heat to medium low, return chicken to pan, cover and cook 8 to 10 minutes more or until chicken is cooked through. Add lime juice.
Meanwhile, to make the avocado sauce combine all sauce ingredients in a small blender and process until smooth and uniform in color.
To serve: Top each chicken breast half with tomato sauce mixture, avocado sauce and garnish with cilantro.