Rinse collard greens under cold running water. Chop leaf portion into 1/2-inch slices and the stems into 1/4-inch pieces for quick and even cooking.
To get the most health benefits from collard greens, we recommend letting them sit for a minimum of 5 minutes before cooking. Sprinkling with lemon juice before letting them sit may be able to help activate their myrosinase enzymes and increase formation of beneficial isothiocyanates in the greens.