Peel and grate the ginger. Push through a small-mesh strainer over a small dish. Discard pulp left in strainer and combine ginger juice, vinegar, wine, shallots, bay (curry) leaf and whole peppercorns in a small, heavy, nonreactive saucepan. Boil over medium-high heat until reduced by half. Add whipping cream, return to a boil, and then reduce to a simmer. Simmer until thickened. Remove saucepan from heat and whisk in a few pieces of chilled butter until they melt into a creamy sauce. Return saucepan to burner. Over very low heat, add remaining pieces of butter, one at a time, whisking constantly. The sauce should be smooth and creamy. Add seasonings to taste as needed. Strain through a fine-mesh strainer. Hold the sauce in a warm area.