Place live clams in 1/4 inch of hot water, cover, and boil 6 to 8 minutes or until they open.
Cool.
Remove clams from their shells, discarding any that do not open.
Chop clams coarsely.
If lobsters are live, plunge them head first into enough boiling salted water to cover them well.
Return water to a boil, reduce heat, and simmer lobsters 10 to 12 minutes.
Take lobsters out of the water, cool, then split lobsters in half lengthwise.
Whether lobsters are freshly poached or purchased cooked, take lobster meat out of shells, dice, and set aside.
Clean the shells out well if they are to be used for presentation.
Melt 2 tablespoons of butter in a heavy saucepan over medium heat.
Saute the shallots and green onions 2 or 3 minutes, until soft.
Add sliced mushrooms and saute 1 minute longer.
Add diced lobster, scallops, shrimp, and clams.
Continue sauteeing gently 2 or 3 minutes longer, remove seafood and vegetables from the pan with a slotted spoon.
Pour in the white wine.
Raise the heat to high and reduce the wine to 3 or 4 tablespoons, stirring frequently.
When wine is reduced, pour in the cream and reduce again, stirring constantly, until sauce measures a scant 2 cups.
Lower the heat and return sauteed seafoods and vegetables to the sauce.
Simmer 2 or 3 minutes, then season with salt and white pepper, to taste, and cayenne pepper, if desired.
Divide the lobster mixture evenly among 4 ramekins or 4 lobster shells.
Sprinkle with bread crumbs, and dot with remaining 2 tablespoons butter.
Bake in a preheated 350 degree oven until lightly browned on top.
Do not allow mixture to boil or sauce may separate.