To make the sauce, quickly add a teaspoon or so of oil (if needed) to lightly coat the base of the pan.
With the pan over medium-high, add the shallots. Cook until the shallots begin to soften. Next, add the mushrooms, along with the butter. Once the mushrooms have taken on some color, add the minced garlic. Let cook for approximately 30 seconds.
The next step is to deglaze the sucs. It is important to remove the pan from the flame before adding the liquor.
NOTE: FOR SAFETY REASONS, DO NOT ADD THE LIQUOR TO THE PAN DIRECTLY FROM THE BOTTLE OR WHILE THE PAN IS OVER THE FLAME.
Once the liquor has been added, return the pan to the stove. Stand back and tilt the pan away from you to allow the flame to ignite the liquor. Set the pan down and let the alcohol cook and burn off.
Note: If using an electric range, refer to the drill-down on How to Flambe with an Electric Burner.
Once the flame has died, let the juices reduce by half to concentrate. Then add the Dijon, Worcestershire sauce, cream and any juices from the resting steaks. Let the sauce simmer and reduce to thicken.