1 tablespoon cornstarch dissolved in 1/4 cup water
8 medium flour tortillas, warmed
1/3 cup hoisin sauce
2 tablespoons reduced-sodium soy sauce
2 tablespoons water
1 tablespoon dark sesame oil
2 teaspoons sugar
2 cloves garlic, minced
Soak mushrooms in 1 cup hot water 20 minutes or until softened. Drain well; remove and discard stems. Cut caps into thin strips.
Cut beef steak lengthwise in half, then crosswise into thin strips. Stack 3 or 4 strips at a time; cut lengthwise in half. Combine marinade ingredients in large bowl. Add beef; toss. Refrigerate 20 minutes.
Drain beef, discarding marinade. Heat large nonstick skillet over medium-high heat until hot. Add 1/2 of beef; stir-fry 1 to 2 minutes or until outside surface of beef is no longer pink. (Do not overcook.) Remove. Repeat with remaining. Combine beef, mushrooms, coleslaw mix, green onions and cornstarch mixture in skillet. Cook and stir until sauce is thickened and bubbly.
Spread hoisin sauce on tortillas; spoon beef mixture down center. Fold bottom edge over filling; fold right and left sides to center, overlapping.