Squeeze the juice of the lemon into a small bowl.
Take 8 slices of anchovies out of the tin, cut them into long, thin strips. Add these to the lemon and marinate for 10 minutes.
Meanwhile, remove & discard the woody end bit of the fennel. Then cut off the stems, leaving the bulb whole, and slice it up thinly.
Cut off the leaves of the celery - put these aside.
In a bowl, mix the sliced vegetables, add the celery leaves, chopped dill and finely the anchovies with the lemon juice. Mix well, season to taste.