Prepare 1 cup white sauce
Melt over low heat, 2 tablespoons butter.
Add and blend over low heat for 3 to 5 minutes, 1 1/2 to 2 tablespoons flour.
Stir in slowly, 1 cup milk
For better consistence, you may scald the milk beforehand; but be sure to avoid lumping, that the roux is cool when you add it.
1 small onion studded with 2 or 3 whole cloves, 1/2 small bay leaf.
Cook and stir the sauce with a wire whisk or wooden spoon until thickened and smooth.
1/2 cup whipping cream.
Rub through a fine sieve, 2 table spoons shrimp butter.
Instead of shrimp butter, you may add 1 tablespoon finely ground shrimp made into a smooth paste with 1 tablespoon butter. Heat to boiling point.
Season to taste and garnish with finely chopped shrimp.