Heat oil in a fry pan. Add onions, artichoke and mushrooms and saute until softened. Add crab, wine and herbs, cook over medium heat until wine has reduced by 2/3. Add cream and cook until sauce thickens to sauce consistency. Season with salt and white pepper. Sauce Hollandaise Place egg yolk in a stainless steel bowl, add wine. Place bowl over pot of water, rolling at a gentle simmer. Whisk mixture constantly until it starts to thicken. Remove bowl from heat, and SLOWLY whisk in melted butter. Finish with lemon juice. Assembly: Place Artichoke bottom in center of plate. Fill with crab mixture. Spoon hollandaise sauce over top. Brown with broiler in oven, if desired.