The strongest tasting of the so-called bitter greens—mustard has a sharp, biting peppery taste that can sting like a strong radish. Even cooked mustard greens will have a “bite”. Both the leaves and stalks of mustard greens can be eaten. But both will become tough and more pungent tasting as the weather warms. Salt is a friend to bitter greens, whether you plan to eat them raw or cooked. Mellow the bitter flavor with a sprinkle of salt on endive or radicchio, or include anchovies or cured meat (like bacon, pancetta, or proscuitto) along with mustard, beet, or collard greens.