These ones are assertive; mustard greens can be tough, bitter and spicy … in the absolutely best way! They are sassy. They come in red or green and are a staple of Southern cooking; most commonly braised or slowly cooked, yet young tender raw leaves can be a notable addition to salads. Mustard greens are a gold mine of vitamins K, C, and A, along with folic acid, phytonutrients and essential minerals. When purchasing, look for crisp green leaves and once home, they can be stored in a plastic bag in the refrigerator for up to one week.