In a large heavy-duty skillet, heat the oil over medium-high heat. Season chicken with salt and pepper then add the chicken and cook for 7-8 minutes, turning once or until chicken is cooked through. Remove chicken from skillet and cover with foil on a separate plate, set aside.
Add onions to the same skillet (without washing it) and cook onion for 1 minute. Add garlic and cook for just 30 seconds. Add chicken broth, lime juice, cilantro, red peppers flaked, and salt and pepper to taste. Bring to a gentle boil for 8-10 minutes or until liquid is reduced by 1/4 cup.