Cut scallops in half, then cut into thin cross wise slices.
Combine with the boiling water, lemon juice, onion, parsley, bay leaf, and salt in a large saucepan; simmer, uncovered, for 3 minutes.
Drain, reserving 1 cup liquid, and set aside.
Heat 2 tablespoons butter with the garlic in the saucepan; blend in the flour and cook until mixture bubbles.
Remove from heat.
Add the 1 cup reserved scallop liquid gradually, blending well.
Bring rapidly to boiling and boil 1 to 2 minutes, stirring constantly.
Set aside and keep warm.
Heat the 1/4 cup butter in a skillet; add mushrooms and cook about'5 minutes, or until lightly browned, stirring occasionally.
Blend the mushrooms, tomatoes, and scallops into the sauce and heat thoroughly.
Stir in the bacon; spoon mixture into patty shells; replace pastry lids.
Reserve remaining mixture for sauce.
Thread colored picks with a carrot curl, small gherkin, cut in half lengthwise, and a bacon curl; insert securely in rim of patty shell.
Serve immediately with the hot sauce in a gravy boat.