Combine 1¼ cups (300 milliliters) red wine with 2 tablespoons (30 milliliters) finely chopped shallots, 1 teaspoon (5 milliliters) crushed black pepper, a sprig of fresh thyme, and half a bay leaf. Reduce the mixture by three-fourths. Add 6 tablespoons (90 milliliters) demi-glace or 2 tablespoons (30 milliliters) glace de viande to the reduction. Gently simmer for 15 minutes, being sure to skim off any scum that floats to the surface. Add water or stock as necessary if the sauce becomes too thick. Strain the sauce through a fine chinois into a clean saucepan. If the sauce is too thin, adjust its consistency by stirring in 1 tablespoon (15 milliliters) glace de viande. Add 1 teaspoon (5 milliliters) lemon juice and 2 ounces (60 grams) beef marrow cut into dice or rounds or butter cut into cubes. Season with salt and pepper.