Heat oil in a large frying pan over medium-high heat.
Add the chicken and cook until browned on all sides, about 3-4 minutes, stirring occasionally.
Pour the BBQ sauce and pineapple juice over the chicken and stir well.
Cook for 4-5 minutes or until the sauce is thickened and evenly coats the chicken.
Season with salt and pepper.
Toss onion, pineapple and green pepper with lime juice, salt and pepper in a medium bowl.
Divide amongst bowls, and top with lettuce, sour cream, corn, sliced avocado, and lime wedges.