To make the "white" mirepoix, mix the onion, lemon grass, celery, and leek and refrigerate until cold, at least 4 hours, preferably overnight. (In combination with the fish and egg whites, the mirepoix will form the clarification to make the consomme crystal clear. This combination of ingredients will form what is referred to as a raft that essentially coagulates as the consomme clarifies.) Mix the chilled mirepoix, ginger root, fish scraps, shrimp shells, and egg white and add to a stockpot. Pour in the chilled fish stock. Add the lemon juice. Bring to a simmer (just below a boil in classical cooking) over low heat, stirring frequently so that the clarification ingredients remain free floating. Please note that the heat must be kept at a simmer, low enough so that the raft which is forming does not break apart from the action of cooking and high enough to cook out the impurities so that they can be collected in the raft. Once the raft forms and rises to the surface, cease stirring. However, gather some broth from the edge of the pot and baste the raft to keep it from breaking apart. After 60 to 90 minutes at the correct simmer, the raft will begin to sink, at which point the consomme is finished.
For the edamame, add soybeans in their pods to a pot and cover with water. Boil until tender, about 10 minutes. Drain and set aside until cool enough to handle. Remove soybeans from their pods and set aside until needed.
In a food processor blend shrimp, egg whites, scallions, salt and pepper to a paste. Spoon some of this mixture into a pastry bag with a 1/2-inch plain tip. Pipe tiny dumplings into the consomme and poach.
Spoon 1/4 cup edamame into bowls, and ladle soup over.