It's crab season here in the San Francisco bay area. Heap and heaps of luscious Dungeness crabs are showing up all over the place. Steamed or live++take your pick! I was in Oakland's Chinatown last weekend shopping at the Sam Yick gorcery and saw a couple of boxes of stillkicking Blue crabs for a buck seventy-nine a pound. Good eatin' ahead! Kill and clean the crab. Place it, top shell down, on a heatresistant plate. Scatter the onion, ginger and wine on top of the crab. Put the crab and plate into a preheated steamer. steam over high heat for 15 minutes. Remove and cool. Disjoint and crack the crab and arrange on a platter. Dip the meat into the dipping sauce and eat with green onions and ginger. Use the tip of the leg to dig out the meat. Serves 2 as a light meal. GINGER, GREEN ONION and VINEGAR DIPPING SAUCE Scatter green onions in a shallow saucer. Top with the shredded ginger. Sprinkle sugar and salt evenly over the ginger. Pour the vinegar over the ginger. Heat the oil until it's hot but not smoking, and pour it over the mixture. It should sizzle lightly. If it is too hot, let it cool. Makes about two third cup. Joyce Jue, San Francisco Chronicle, 2. 0.044444444444444.