1. Combine lime juice, chile powder, Worcestershire, and cumin in a medium bowl. Add beef; toss well.
2. Heat oil in a large nonstick skillet over medium-high heat. Add onion and bell peppers to pan; sauté 4 minutes or until onion is almost tender, stirring occasionally. Add mango and tomato to pan; sauté 1 minute. Add beef mixture; sauté 2 minutes or until desired degree of doneness, stirring occasionally. Add soy sauce; cook 15 seconds. Remove from heat; stir in cilantro.
3. Heat tortillas according to package directions. Place 2 tortillas on each of 2 plates; top each tortilla with about 3/4 cup beef mixture. Top each tortilla with 1 1/2 teaspoons prepared salsa and 1 1/2 teaspoons sour cream.