Preparing Knobbly Vegetables

Celeriac, Jerusalem artichokes and kohlrabi are all knobbly vegetables that look difficult to deal with, but the technique of preparing them is remarkably simple. First peel off the skin with a small paring knife, then slice, chop, shred or grate the flesh, depending on future use (see box). Once the flesh is cut, immerse the pieces in acidulated water immediately to prevent discoloration (see box).