In a pot over medium-high heat, add brown sugar, teriyaki sauce, orange juice, bourbon, ginger, garlic, Weber’s Cowboy Seasoning, and cornstarch slurry and whisk until glaze reaches desired thickness. Remove from heat and set aside.
Coat steak in oil and season generously with Weber Cowboy Seasoning. Grill steak until medium rare or they read 130 degrees on a meat thermometer (4-5 minutes per side) or until desired doneness is reached.
Brush both sides of the steak with the teriyaki bourbon sauce. Remove steak from the grill and let rest for 5-10 minutes.
Cut along the bone to remove the meat. Slice meat into strips and sprinkle more cowboy seasoning and teriyaki bourbon sauce over the top.