The steakhouse classic, traditionally prepared tableside, gets the grill treatment here. The cooking goes fast, so have all your ingredients measured and next to the grill beforehand. If time allows, salt the steaks and chill, uncovered, for up to 3 days before grilling—they’ll be even more thoroughly seasoned and tender.
Preheat a grill to medium-high (about 450°). Generously salt steaks on both sides.
Thread mushrooms onto 4 (8-in.) skewers and brush with oil. Grill mushrooms, turning occasionally, until well browned and cooked through, about 15 minutes.
Meanwhile, finely chop shallots. Heat 2 tbsp. oil in a large cast-iron skillet on grill. Add shallots and cook, stirring often, until tender, 3 to 4 minutes. Add sherry; cook until reduced by half, about 2 minutes. Stir in broth, mustard, Worcestershire, cream, and salt and pepper to taste. Simmer until slightly reduced and beginning to thicken, 3 to 4 minutes. Add butter and cook, stirring, until butter melts. Remove skillet from grill and cover to keep warm.
Season steaks with pepper and grill about 2 minutes per side for medium-rare. Let rest 5 to 10 minutes on a platter. Push mushrooms off skewers and cut in half or thickly slice.
Arrange steaks on plates. Drizzle with a bit of juice from the platter if you like, then the shallot sauce. Top with mushrooms and chives. Arrange some dressed watercress next to each steak.
Servings 0
* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.
