You can use this easy, old-fashioned brown gravy recipe for all kinds of cuts of beef, from filet mignon to petite filet to roast beef to London Broil.
Once you have pan-seared and/or finished cooking your filets in the oven, remove the meat, tent it with foil to keep warm, and don‘t clean that pan! Leave 3 tablespoons of the pan drippings in the pan, and drain off any extra oil.
Return the pan to medium heat and melt the butter. Add the garlic and onions, and sauté, stirring frequently for 3 minutes, until the vegetables have softened slightly. Sprinkle over the flour and whisk until the flour is incorporated into the base and toasted, about 2 minutes. Add the red wine and whisk for a minute until it is mostly evaporated. Pour in the broth, and stir and scrape until the browned bits release from the bottom of the pan. Add salt and pepper and the sherry vinegar. Whisk until smooth.
Pour the sauce into a mesh strainer and press the sauce through. Discard any solids left on the strainer.
Serve the sauce warm on the side, or drizzle the sauce over the meat.
Notes
Tips for the Smoothest Gravy
Sprinkle the flour into the pan instead of dumping it all in.
Make sure there are pan drippings or some fat in the pan, and make sure you whisk frequently so that the flour toasts and blends in smoothly. This will make a roux, which is the base for your gravy. Allow the flour to toast for a bit before adding the liquid.
Add the liquid (broth, wine, water, stock) gradually and whisk constantly as you pour.
Strain the gravy through a mesh strainer, pressing it through, and discarding any solids left behind in the strainer.