How to Make It
Heat a grill pan over medium-high heat. Coat pan with cooking spray. Add bell pepper to pan, and cook 4 minutes. Add onion to pan, and sauté 10 minutes or until vegetables are tender. Place pepper mixture in a large bowl; cover and keep warm.
Add beef to pan; cook 7 minutes or until desired degree of doneness. Add to pepper mixture. Add chili powder, juice, oil, salt, and garlic to bowl; toss to coat.
Heat tortillas according to package directions. Spoon steak mixture evenly over 8 tortillas. Top each taco with about 1 teaspoon cilantro and 2 1/4 teaspoons sour cream.