Serves 4 as main course, 8 as appetizer.
Requires 4 or 8 2 oz. ramekins.
Preheat oven to 350° F with rack placed in the middle.
Toast bread crumbs in the oven on a baking sheet until light golden colour, about 6 minutes. Transfer to a bowl and mix in the cheese. Set aside.
Combine wine, verjus, water, onion, bay leaf, salt and pepper in a 3 quart heavy saucepan. Bring to a simmer and simmer, uncovered for 5 minutes. Add the scallops and simmer, stirring once in a while, until just cooked through, 2 or 3 minutes. Remove scallops with slotted spoon and transfer to large plate to cool. Return any onions to the pan. Boil liquid until reduced to 1 cup, 8 to 10 minutes. Strain liquid through a sieve into a bowl and discard solids.
Melt 2 tablespoons of butter in a 10 inch heavy bottom fry pan over medium heat. Add mushrooms and cook, stirring occasionally, until most of the liquid from the mushrooms has evaporated, about 5 minutes. Season with salt and pepper and remove from heat.
Whisk together cream and egg yolk in a heat proof medium bowl. Melt 2 tablespoons butter in a 2 ½ quart saucepan over moderately low heat. Add flour and cook, whisking, for 2 minutes to make a roux. Remove pan from heat and add reduced cooking liquid, whisking constantly. Return pan to heat and simmer, whisking for 1 minute. Pour sauce in a slow stream into cream mixture, whisking constantly. Pour sauce back into pan and simmer, 1 minute. Remove pan from heat and season with salt and pepper.
Set broiler rack about 4 inches from heat and preheat broiler. Stir mushrooms, scallops and cooked crab, if using, into sauce. Divide mixture among ramekins. Sprinkle with bread crumb mixture and place ramekins on baking sheet. Dot with remaining butter.
Broil until golden, about 2 minutes. Sprinkle with parsley.
**The scallop mixture can be made a day ahead and refrigerated, covered. Reheat in a heavy saucepan over medium heat, stirring constantly, before spooning into ramekins.
Pair with Venturi-Schulze 2006 Kerner.