1. After being separated into stalks, they must be thoroughly rinsed and then trimmed of all thorns and leaves. Christopher Hirshiemer2. The indigestible stringy fibers are then cut off with a vegetable peeler and cut into 1 1⁄2″ -2″ pieces. Christopher Hirsheimer3. Before the chopped-up stalks are parboiled, which reduces bitterness, they are usually rubbed with lemon and set aside in acidulated water to prevent discoloration. Christopher Hirsheimer