Season fillets with pepper. Heat 1/3 of butter in a large sauce pan. Add onion and cook to a golden puree. Add creams, salt, pepper, and nutmeg to taste. Add another 1/3 of butter. Simmer the fillets in the sauce. When the fillets are cooked, transfer to a heated serving dish. Strain sauce into a clean pan and bring to a boil. Remove pan from heat and whisk in the remaining butter. Pour sauce over fish. Garnish with pastry diamonds or croutons.{$7e}(Original recipe for 6)
