Grilled Beef Fajita Packs

Name: Grilled Beef Fajita Packs
Ingredients: 1 lb boneless beef sirloin steak, cut into thin strips; 1 medium green bell pepper, cut into 1/2-inch strips; 1 medium red bell pepper, cut into 1/2-inch strips; 1 medium yellow bell pepper, cut into 1/2-inch strips; 1 medium onion, thinly sliced; 1 package (1.25 oz) fajita seasoning mix; 1/3 cup water; 8 Old El Paso™ flour tortillas for soft tacos & fajitas (from 10.5-oz package); 3/4 cup Old El Paso™ Thick 'n Chunky salsa, if desired; 3/4 cup sour cream, if desired