Prepare Dipping Sauce. Meanwhile, thaw shrimp and sole, if frozen. If desired, brown steak on both sides in a lightly oiled large skillet over medium-high heat. Transfer beef to a cutting board. Thinly slice beef into bite-size strips. Arrange beef and seafood on a platter; set aside.
Arrange cabbage, mushrooms, bean sprouts, carrots, and bamboo shoots on a separate platter; set aside.
In a large saucepan bring water and salt to boiling. Pour into a firepot, electric wok, or electric skillet. Light burner under pot or turn on wok or skillet to medium heat.
To serve, give each person a bowl and a small wire strainer, chopsticks, or a slotted spoon. Dip meat, fish, and shrimp into simmering water until done. Allow 30 to 60 seconds for beef or until desired doneness and 1 to 2 minutes for fish (should flake easily) and shrimp (should turn opaque). Remove from water and place in bowls. Add vegetables to pot. Cook 1 to 2 minutes or until crisp-tender. Remove from water and add to bowls. When all meat, fish, shrimp, and vegetables are cooked, add green onions, ginger, and noodles to broth. Cook 3 minutes or until noodles are tender. Remove and discard ginger pieces. Pour broth and noodles over meat and vegetables in bowls. Stir Dipping Sauce into each bowl to taste. Makes 6 to 8 servings.
In a small bowl stir together soy sauce; cilantro; green onions; toasted sesame oil; jalapeno pepper (optional); sugar; rice vinegar; ginger; and garlic. Allow to stand, covered, 1 hour before serving. Makes about 3/4 cup.