Instructions

1. Marinate steak:

   Whisk together cola, bourbon, brown sugar, Worcestershire sauce, balsamic vinegar, and 1 teaspoon of the kosher salt in a medium bowl until sugar has dissolved. Place steak pieces in a large ziplock plastic freezer bag. Pour 1 cup of the cola mixture over steak; seal bag, and refrigerate 4 to 12 hours. Refrigerate remaining cola mixture in an airtight container until ready to use.

2. Grill steak:

   Remove steak from refrigerator; let stand at room temperature 30 minutes. Preheat grill to high (450°F to 500°F). Remove steak from marinade, and place on a paper towel-lined plate; discard marinade. Thread steak onto 8 skewers (about 5 pieces of steak per skewer). Pat kebabs dry with paper towels, and sprinkle with pepper and remaining 1 teaspoon kosher salt. Place kebabs on oiled grates. Grill, uncovered, turning every 2 minutes, until steak is medium-rare and charred on all sides, about 8 minutes. Remove to a plate, and cover loosely with aluminum foil. Let rest 15 minutes.

3. Prepare sauce:

   Meanwhile, pour reserved cola mixture into a small saucepan, and bring to a boil over medium-high. Reduce heat to medium, and simmer, stirring occasionally, until mixture is reduced to about 1/4 cup, 10 to 12 minutes. Stir in butter, and continue to cook over medium, stirring often, until sauce thickens slightly and lightly coats the back of a spoon, 1 to 2 minutes. Drizzle sauce over kebabs. Suggestion: serve with Smashed-Cucumber Salad.