Put out a variety of fresh, flavorful ingredients so guests can assemble their own salad or open-face sandwich.
For relish, stir together mushroom, green onion, Worcestershire sauce, oil, and pepper. Cover and chill for 2 to 24 hours.
To serve, set out the relish, greens, beef, cheese, sliced tomato, onion, and olive in serving bowls or on platters. If desired, garnish tomatoes and beef with fresh rosemary sprigs. Add baguette slices and/or breadsticks to the buffet. Invite guests to assemble their own salads or open-face sandwiches. Makes 16 to 20 servings.
Prepare the recipe three times.