How to Make It
Melt the butter in a heavy saucepan. Add the shallot, garlic and celery and cook over moderate heat until lightly browned, 3 minutes. Stir in all of the remaining ingredients and gradually bring to boil. Reduce the heat slightly and simmer the sauce until thick and richly flavored, 8 to 10 minutes, whisking from time to time. Season the sauce with salt and pepper.