Melt 4 ounces of the butter in a skillet. Add the Creole seasoning, clam juice, garlic and shrimp. Saute until the shrimp are pink. Add the mushrooms, parsley, and scallions. Saute until the mushrooms are tender, about 2 to 3 minutes. Add the remaining 2 ounces of butter and continue cooking until the sauce is creamy. Server over French bread rounds in shirred egg dishes or shallow soup bowls.