If you would like this relish to be spicy, add ½ teaspoon of mustard seeds.
Wash the celery and separate the stalks. Using a sharp knife at an oblique angle, cut down through the base of each stalk from the inside just to the outer edge. Carefully break the base away, pulling any tough strings on the outer peel down and away from the stalk. Turn the stalk around and cut off the tip in a similar manner, pulling any stringy outer peel away. (If you prefer, you can peel o