Preheat oven to 350 degrees F. Heat oil in large saucepan or Dutch oven over medium-high heat. Add onion and cook, stirring often. 10 minutes or until golden. Add jalapeno pepper, chili powder, garlic, oregano and cumin; stir 1 minute more. Add 1 tablespoon water and stir; remove from heat. Stir in sweet potato, beans, corn, bell pepper and lime juice.
Spoon 2 tablespoons cheese in center of each tortilla. Top with 1 cup filing. Fold all 4 sides around filing to enclose. Place burrito's seam side down on baking sheet. Cover with foil and bake 30 minutes or until heated through. Serve with sour cream, if desired.