3 small English cucumbers
7 cans albacore tuna (drained and flaked)
2 tablespoons mayonnaise (or to taste)
1 stalk celery with leaves (finely diced)
2 scallions (white and light green part, finely minced)
12 tablespoons fresh minced dill or tarragon
  grated zest of 1 lemon
  freshly ground pepper
  fresh dill or tarragon sprigs (as garnish)