Red Wine Sauce with Beef Marrow

• ½ oz (15 g) unsalted butter
• ½ teaspoon chopped shallot

In a saucepan, heat half the butter and, when very hot, add the shallot and brown lightly. Add the wine, seasoning and herbs, bring the sauce to the boil, and reduce rapidly until 2 tablespoons remain. Add the meat glaze and boil for 15 minutes. Strain the sauce through a very fine sieve; bring to t