Put chicken in a zip lock bag and toss with lime juice, garlic, cumin and oregano. Allow to marinate for 30 minutes in the refrigerator.
Meanwhile, heat vegetable oil in a large saute pan over medium-low heat. Add the peppers and onions and cook, covered, for 20 minutes or until tender, stirring occasionally.
After 30 minutes, remove chicken from the refrigerator. Grill over medium-high heat until cooked through, about 5 minutes per side. Remove from grill and allow to cool slightly. Slice into strips. Put chicken on top of lettuce, and top with sour cream, cheese and cilantro-lime vinaigrette.
Puree all ingredients in a food processor until smooth.
by The Savvy Kitchen