Directions
1. Pour beef stock into a large saucepan. Simmer the stock over medium-high heat until it has reduced to about ½ cup. This should take about 1 hour.
2. While the stock is reducing, season the steaks with salt and pepper on both sides.
3. In a large skillet, preferably cast-iron, heat 2 tbsp of butter and the olive oil. When the butter has melted completely, and the oil has developed a shimmer on the surface, add your steaks.
4. Brown your steaks on both sides, about 3 minutes per side. Move the steaks to a plate and cover them lightly with foil.
5. Add the mushrooms and shallots and stir frequently. Add oil if the pan starts to become dry. Stir for two minutes and add the garlic.
6. When the garlic develops color, add in the brandy being cautious because it can ignite from the heat. This is normal.Add the wine, being careful again because it can ignite too. Add in the mustard and Worcestershire sauce, followed by the beef stock you have reduced. Allow simmering for between 2 to 3 minutes.
7. Place the steaks back into the pan to finish cooking in the liquid mixture. Finish cooking to the desired temperature. This should be between 2 to 4 minutes longer, depending on how you prefer your steak. Test your steaks with an instant-read thermometer. For the recommended medium-rare, the temperature should be 135. Add the rest of the butter to the sauce and allow it to melt.
Serve each steak on a plate with desired side dishes. Divide the sauce between the steaks once they are plated.
Recommended Side Dishes:
Mashed Potatoes and Roasted Asparagus