Simmer 2 minced shallots, 3 crushed peppercorns, and 1 tablespoon minced fresh tarragon (or 1 teaspoon dried) with 4 tablespoons wine vinegar. Reduce liquid to about 1 tablespoon. Strain liquid into heavy pan, or top of double boiler. Proceed with Hollandaise recipe, omitting the tablespoon water.
Finish with minced fresh tarragon and chervil, or, lacking these, minced parsley and a few chopped chives.