Heat oil in 12-inch skillet or wok over medium-high heat until hot. Add beef strips, salt, garlic and chile; cook and stir 3 to 5 minutes or until beef is browned and of desired doneness. Remove beef from skillet; cover to keep warm.
In same skillet, combine bok choy and bell pepper; cover and cook 4 to 6 minutes or until vegetables are crisp-tender, stirring occasionally. Return beef to skillet. Add hoisin sauce; cook and stir 1 minute or until thoroughly heated.
Meanwhile, heat tortillas as directed on package.
To serve, spoon about 1/2 cup beef mixture down center of each warm tortilla. Fold or roll up each tortilla.