Chef Julia Child
1 pound Celery Root (Celeriac), cut 3 - 3½ inch across
1½ teaspoon Salt
½ teaspoon Lemon Juice
¼ cup Dijon Mustard
3 tablespoons Boiling Water
⅓ cup Olive Oil or Salad Oil
2 tablespoons Wine Vinegar
Salt and Fresh Ground Black Pepper
2 tablespoons Organic Parsley, chopped
Work quickly to prevent the celery root from discoloring.
Peel the brown outside off the celery root with a short stout knife (don't try to get every bit of peel out of every crack!), cut into chunks and shred in a food processor.
At once, toss it in a bowl with the salt and lemon juice. (If you are doing a lot, shred and season in batches in order to prevent yellowing.)
Meanwhile warm a mixing bowl in hot water and dry it.
Add the mustard, and by dribbles whisk in the boiling water, then the oil; finally dribble and whisk in the vinegar to make a thick creamy sauce.
Taste the celeriac and if it seems salty, rinse it in cold water, drain, and dry.
Fold it into the sauce, and correct seasoning.
Fold in the chopped parsley.
Serve immediately or after marinating in the refrigerator.