1 large celery root, peeled
Juice of 1/4 lemon
1 cup vegetable oil
Juice 1/4 lemon into a big pot of water and put it on to boil.
Julienne the peeled roots by using a mandoline (a device with adjustable blades) on the French-fry setting. If you don't have a mandoline, peel the roots, cut them into 1/4-inch slices, then into 1/4-inch sticks, and put them in a bowl of acidulated water.
Add celeriac to the pot of boiling water and blanch for 5 minutes. Drain and dry well.
In the same pot or a deep-fryer, heat the vegetable oil until smoking (about 350 degrees) and start deep frying in batches until golden. Drain on paper towels and sprinkle with salt. Reheat in the oven before serving.