In a non-aluminum saucepan, combine shallots with the wine. Reduce liquid to 1 or 2 tablespoons. Remove from heat and add one chunk of butter, stirring with a whisk to blend. Slowly add all the pieces of butter until well combined. If you need to return the sauce to the heat to incorporate all the butter, do it over very low heat, or the sauce will break. Strain the sauce through a fine mesh strainer and serve immediately, or hold in a double boiled over barely simmering water, or in a Thermos.