Thaw shrimp, if frozen. Partially freeze chicken and beef for easier slicing. Peel and devein shrimp; rinse shrimp and pat dry with paper towels. Thinly slice chicken crosswise into bite-size strips. Thinly slice beef across the grain into bite-size strips. Arrange shrimp, chicken, and beef on a platter, keeping meats separate.
In a large saucepan combine broth, green onions, garlic, peppercorns and, if desired, crushed red pepper. Bring broth mixture to boiling. Pour into a fondue pot. Return to boiling.
To serve, give each person a fondue fork. Dip beef, chicken, or shrimp into broth; cook shrimp until opaque, chicken until no longer pink, and beef until desired doneness (allow 1 to 3 minutes for each piece). Serve with Ginger-Wasabi Sauce and/or Lemon-Pepper Aioli.