Many recipes for casseroles, salads and soups call for finely chopped, or minced, celery. Mincing is a basic cooking skill that isn't difficult but requires a knack with the knife and some practice. Select firm, light green celery with fresh, bright leaves and no bruises, discoloration or wilting. Avoid soft, limp celery.
Pull the celery stalks apart. Discard damaged stalks and then rinse the stalks thoroughly to remove sand and dirt.
Trim the leaves from the top of the stalks, then cut off the thick, white bottoms.
Cut the celery into uniform, 2- to 3-inch lengths, using a chef's knife, then cut each stalk lengthwise into thin strips about 1/8 inch in diameter.
Hold the strips with your non-cutting hand, then cut across the strips to produce evenly diced cubes measuring about 1/8 inch.
Gather the celery into a neat pile. Steady the tip of the knife against the cutting board, using the fingertips of your non-cutting hand. Grasp the knife handle in your other hand and use a steady rocking motion, with the tip remaining on the board, to mince the celery.
Move the knife a 90-degree angle. Continue to rock the blade back and forth until the celery is very fine. However, don't over-chop, as excessive chopping results in mushy texture and loss of nutrients.