Clean the mushrooms and trim the stalk tight to the cap, if necessary. Using 6-inch bamboo skewers, stick a skewer into three or four mushrooms and arrange on a large platter or baking pan. Cover and refrigerate until needed.
Prepare the marinade: In a small bowl, combine all the marinade ingredients and pour over the mushrooms, turning to coat all sides. Let marinate, unrefrigerated, about 15 minutes.
Preheat the grill or broiler while the mushrooms marinate.
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 sauce, and chili pepper flakes, then cook 1 or 2 minutes longer. Strain into a clean pan and whisk in the remaining 4 tablespoons butter. Keep warm.
Arrange the skewers on the grill or under the broiler* being careful that the bare ends of the skewers are not directly over (or under) the flame. Grill until cooked, turning after 2-3 mins.
Presentation: Pour the sauce into a small bowl and set in the center of a large serving platter. Arrange the skewers around the bowl and serve immediately.
Makes 6-10 skewers
Chef Wolfgang Puck