Heat a large skillet to medium heat. Add avocado oil, onion and bell peppers. Saute for 2-3 minutes.
Add beef and brown, stirring occasionally. (If making dairy free sour cream, make while meat is browning). Once meat is cooked through, add tomatoes, onion powder, paprika, chili powder, cumin, salt and cayenne pepper. Stir and cook another 1-2 minutes.
Serve over butter lettuce leaves. Top with avocado and dairy free sour cream.