Soak skewers in cold water and refridgerate for one hour.
Cut Steak into 24 3"long x 1" wide -inch strips, each weighing about 1/2 ounce. Skewer each piece on a six inch skewer. Refridgerate until needed.
Prepare the marinade: In a small bowl, combine all the marinade ingredients and pour over the meat, turning to coat all sides. Let marinade, unrefrigerated, about 15 minutes.
Preheat the grill or broiler while the steak is marinating.
Prepare the sauce: In a small skillet, melt 2 tablespoons butter. Add the garlic and green onion and saute over medium-high heat until soft, about 2 minutes. Pour in the stock, soy, and chili pepper flakes, and cook 1 or 2 minutes longer. Stain into a clean pan and whisk in the remaining 4 tablespoons butter. Keep warm.
Broil skewers of steak until medium rare, about 30 to 40 seconds each side. Be careful not to burn skewers.