Sea Treasure Clam Miso Soup

Preparation Squeeze thawed ginger over small bowl to extract 1 teaspoon juice. Set aside. Combine 2 cups Dashi and 2 cups water in large pot over medium-high heat. Add clams. Cover; simmer until clams open, about 10 minutes (discard clams that do not open). Remove from heat. Transfer clams to bowl. Remove meat from shells; reserve meat and shells separately. Strain broth and any accumulated juices through fine strainer lined with coffee filter. Return broth to pot. Mix white and red misos in bowl. Bring broth to simmer. Add 1/4 cup broth to miso; stir until miso dissolves. Whisk miso into broth in pot. Add reserved ginger juice and soy sauce. Keep warm over medium-low heat (do not boil). Place 1 clam shell in each bowl. Place 3 pieces clam meat in each shell. Ladle broth over; sprinkle with onion.