Reduce the Sauce Espagnole to 3/4 of its original volume. Add the larger amount of wine and the Glace de Viande. Drop in some melted butter, a bit at a time, while swirling the contents of the pan, by moving the pan -Not By Stirring-, gently. Also add the smaller portion of wine. Do Not Allow The Sauce To Boil! Do Not Stir The Sauce! Serve at once, while the butter swirl is visible.