Sprinkle chicken with lemon juice; set aside. In a large skillet, saute garlic in oil for 1 minute. Add the peppers, onion, oregano, cumin and pepper flakes. Reduce heat; cover and simmer for 10 minutes.
Add the chicken, salt and pepper; cover and simmer for 10-15 minutes or until vegetables are tender and chicken is no longer pink. Sprinkle with cilantro.