Preheat oven to 350 degrees F. Wrap tortillas in foil. Warm in oven until heated through, about 15 minutes.
Meanwhile, combine onion and oil in large nonstick skillet. Stir over medium heat until onion is golden, about 6 minutes. Add cumin and chili powder; stir 20 seconds. Add bell pepper, corn and carrot; saute until almost tender, about 5 minutes. Add beans, tomatoes and jalapeno; bring to simmer. Remove from heat.
Place warm tortillas on work surface. Spoon filling down center, dividing equally. Top each with 2 tbsp cheese, then 1 tbsp each sour cream and cilantro. Fold sides of tortilla over filling, forming packages. Turn each package, seam side down, onto plate.