Shooter's Steak Sandwich

Ingredients (16)

• + 1 tablespoon olive oil add to pantry
• ✓ 1 tablespoon butter, divided
• ✓ 1 ½ pounds button mushrooms, finely chopped
• + salt add to pantry
• + ½ cup minced shallots add to pantry
• + 2 tablespoons brandy add to pantry
• + 1 pinch cayenne pepper, or to taste add to pantry
• + salt and freshly ground black pepper to taste add to pantry
• + 3 tablespoons Dijon mustard add to pantry
• + 1 tablespoon extra-hot prepared horseradish, or to taste add to pantry
• + 1 tablespoon mayonnaise add to pantry
• + 1 (1 1/2) pound round loaf of crusty bread add to pantry
• + 2 (1 pound) beef rib-eye steaks, well trimmed add to pantry
• + 1 tablespoon vegetable oil add to pantry
• + ¼ cup water add to pantry
• + 3 ounces finely textured pate (such as foie gras), sliced add to pantry