(makes enough sauce for a 3 – 4 lb. Tenderloin Roast)
1. Melt 2 tablespoons of the butter in a 1 quart pot, on medium-low heat.
2. Add the shallots and slowly cook until translucent, about 5 minutes.
3. Add the thyme and bay leaf, stir well.
4. Add the port, bring to a boil, reduce heat and simmer for 20 to 30 minutes until reduced by ½.
5. With a fine sieve, strain out all of the solids, wash the pot and return the strained Port to the pot (there should be about 12 or 13 oz.) and re-heat on low.
6. Add the Demi-Glace and whisk until well blended.
7. Add the pepper and set aside until ready to serve. The sauce should be thick enough to coat the back of a spoon; if not, mix a tablespoon of cornstarch with 1/4 cup of cold water until in turns into a paste. Slowly whisk paste to the hot sauce until it is thickened to your satisfaction.
8. Just before serving, re-heat the sauce and add the remaining tablespoon of butter, stir well to finish the sauce.
NOTE: Sauce can be made several days in advance (steps 1-7) and refrigerated. Heat well before serving and finish with step 8.
See: Roast Tenderloin of Beef (Filet Mignon) with Port Wine Reduction Sauce