Ingredients

  • 1 cup Guinness beer, or other stout
  • 1/2 cup finely chopped sweet onion
  • 1/3 cup reduced-sodium soy sauce
  • 2 tablespoons molasses, (not blackstrap)
  • 1 tablespoon chopped fresh rosemary, or 1 teaspoon dried
  • 1 tablespoon minced garlic
  • 1/4 teaspoon Worcestershire sauce
  • 1 pound boneless bison rib-eye steaks, 1 1/2-2 inches thick (see Tip)
  • 24 cremini mushrooms, stems removed
  • 1 large red onion, cut into 1/4-inch-thick slices
  • 2 tablespoons extra-virgin olive oil
  • 1/2 teaspoon kosher salt
  • Freshly ground pepper, to taste
  • 4 slices rye bread, 1/2-3/4 inch thick

Method

  • Combine beer, sweet onion, soy sauce, molasses, rosemary, garlic and Worcestershire sauce in a large sealable plastic bag. Add steaks. Seal the bag, shake and turn it, and refrigerate, flipping over and shaking the bag from time to time, for 12 to 18 hours.
  • Preheat a grill to medium. Remove the steaks from the marinade and pat dry. Reserve 1 cup marinade (discard the rest). Brush mushroom caps and onion slices with oil, sprinkle with salt and pepper and place in a grilling basket. (No grill basket? See Tip, below.) Place the basket on the grill; place the steaks directly on the grill rack. Grill the steaks and vegetables until browned on the first side, 5 to 7 minutes. Turn everything over and grill until an instant-read thermometer inserted into the center of the steak registers 125°F for medium-rare and the vegetables are soft and lightly browned, about 5 minutes more. Remove from the grill and let rest for 5 to 10 minutes. Lightly grill or toast the bread.
  • Meanwhile, place the reserved 1 cup marinade in a small saucepan and bring to a simmer over medium-high heat. Boil until reduced by about half, 7 to 10 minutes.
  • Divide the mushrooms and onions among the pieces of toast and drizzle each with about 1 tablespoon of the reduced sauce. Slice the steak; divide among the sandwiches and drizzle with more sauce. Pour any accumulated juice from the steak over the sandwiches and serve with a fork and knife.