In a large saute pan, over medium heat, melt 3 tablespoons of the butter. Add the mushrooms. Season with salt and pepper. Saute for 2 to 3 minutes. Add the garlic and crab meat. Season with salt and pepper. Saute for 2 minutes. Remove from the heat and stir in the green onions. Set aside and keep warm.
In a stainless steel bowl set over a pot of simmering water over medium heat, whisk the egg yolks with the lemon juice, water, and mustard. Season with salt and cayenne. Whisk the mixture until pale yellow and slightly thick. Be careful not to let the bowl touch the water. Remove the bowl from the pot and whisking vigorously, add the butter, 1 teaspoon at a time, until all is incorporated. Keep warm.
In a large saute pan, melt 1 tablespoon of the butter. Add the asparagus. Season with salt and pepper. Saute for 2 minutes. Remove from the heat and keep warm. Place each piece of veal between a sheet of plastic wrap. Using a meat mallet, pound out very thin. Season both sides of the veal with salt and pepper. Season the flour with salt and pepper. Dredge each piece of veal in the flour, coating each side completely. In another large saute pan, over medium heat, melt the remaining 2 tablespoons of butter. Add the veal and pan-fry for 1 minute on each side. Remove from the heat.
To serve, lay two pieces of the veal in the center of each plate. Spoon the Hollandaise over the veal. Lay four spears of asparagus over each plate of veal. Place a spoonful of the relish in the center of the asparagus. Garnish with the pieces of lemon and parsley.