Soak the bamboo or wooden skewers in water for 30 to 60 minutes. Drain and pat dry. With a sharp knife, cut the steak into 24 long, thin strips. Thread 1 strip onto each skewer, weaving the skewer back and forth along the length of each steak strip. Arrange the skewers on a large platter or baking tray. Cover with plastic wrap and refrigerate until needed.
About 30 minutes before you wish to grill the skewers, combine the soy sauce, honey, chili flakes, cumin, turmeric, and oil in a small bowl. Pour this marinade over the steak skewers, turning to coat the meat evenly. Leave the steak skewers to marinate at room temperature for about 20 minutes.
Preheat a hinged grill or panini maker, according to the manufacturer's instructions, or preheat a broiler, outdoor grill or stovetop grill pan.
Meanwhile, make the sauce: Bring a small saucepan of water to a boil. Add the garlic cloves and blanch them in the boiling water for 30 seconds to a minute to remove some of their harshness. Drain the cloves well, pat them dry with paper towels, and chop them finely. In a small skillet, melt 2 tablespoons of the butter over medium-high heat. Add the garlic, ginger and green onion and saute just until they begin to soften and smell fragrant, about 2 minutes. Add the stock, soy sauce, honey, hoisin or barbecue sauce, and chili flakes and bring to a boil. Cook for 1 to 2 minutes longer. Pour the sauce through a strainer into a clean pan and, over medium heat, whisk in the remaining 2 tablespoons of butter, a little bit at a time. Keep warm.
Grill the skewers (in batches if necessary to prevent overcrowding) until cooked through and nicely browned, about 2 minutes total on a hinged grill or panini maker or 2 minutes per side in the broiler, in a grill pan, or on an outdoor grill (1 minute if you want the meat rare). Take care that the skewers don't prevent a hinged grill or panini maker from closing properly. Transfer to a platter, pour on the sauce, and serve; or serve with the sauce on the side for dipping.