Wash and open the clams; to do so, tap the shell with the back of a knife, open the shells, and take out the meat. Wash and finely slice. Reserve the shells.
Finely dice the scallion, bell pepper, and celery, and put them in a bowl with the pomegranate and clams. Season with lemon juice, grated ginger, lemon zest, minced coriander, salt and pepper to taste.
Put in the fridge for at least half an hour before serving.
Rinse the clamshells thoroughly, dry them one by one, and fill with a spoonful of ceviche. Serve immediately.