Cut steak lengthwise in half, then crosswise into 1/8-inch-thick strips. Combine beef strips and Spice Pack from Stubb's Bar-B-Q Slider Cookin' Sauce kit in large bowl; toss to coat. Heat large nonstick skillet over medium heat until hot. Add half of beef; stir-fry 1 to 2 minutes each or until outside surface is no longer pink. Remove from skillet. Repeat with remaining beef. Return beef to skillet; stir Finishing Sauce from Stubb's Bar-B-Q Slider Cookin' Sauce kit into beef and heat on low about 5 minutes or until heated through and sauce is desired thickness.