This steak and sauce will taste like it took much more effort than it really did.
Melt butter in large nonstick skillet over medium heat. Add shallots and garlic; cook 2 minutes. Stir in mushrooms; cook and stir 3 to 4 minutes. Remove and set aside.
Increase heat to medium-high. Add steaks to skillet; cook approx. 6 to 8 minutes for medium-rare to medium doneness, turning once. Remove to warm platter.
Decrease heat to medium. Add broth, brandy, mustard, Worcestershire sauce and reserved mushroom mixture. Bring to a boil. Cook and stir until liquid is slightly reduced, about 1 minute. Spoon sauce over steaks and sprinkle with parsley.