Heat oil in a large skillet over medium heat. Add bell pepper and jalapeno. Cook until tender (about 5 minutes), stirring often. Add corn and black beans. Stir to combine and continue to cook until warmed (stirring occasionally) for an additional 2 to 3 minutes. Set aside.
Place shredded chicken in a medium microwave-safe bowl. Add barbecue sauce, chili powder and cumin. Stir until combined and chicken is evenly coated. Loosely cover with a paper towel and microwave on high for 1 to 1 ½ minutes, or until heated.
Warm tortillas according to package directions. Spoon chicken mixture in equal amounts in each tortilla and top with black bean and vegetable mixture. Top with sour cream and fresh chopped cilantro, if desired.