While in ancient times, lettuce was used only for the medicinal value of its seeds (the leaves were considered too bitter for human consumption), it is likely the most ubiquitous green vegetable in the Western world today. The three main categories—head lettuce, loose-leaf, and cos/romaine—all offer a light taste, crisp texture, and soft yet firm structure.
Lettuce was first grown by ancient Egyptians as an offering to the gods. This use was passed along to the cultures of ancient Greece and Rome, who included lettuce in the origin stories of their deities. In 86 A.D., Roman emperor Domitian began serving lettuce salads at feasts to stimulate the appetite and encourage digestion. This led to Roman farmers developing many other varieties of lettuce, including the red-leaf varieties common today. More cultivars were created throughout the Middle Ages, and their ease of growth led to a rapid spread throughout the civilized world. By the 1800s, seed catalogs had begun an unscrupulous practice of renaming common lettuce varieties to trick farmers into thinking they were buying several different seeds. This, along with the subtle distinctions between varieties, makes it challenging for seed historians to trace true heirloom lettuces.
While the nutritional value varies with the specific cultivar, lettuce generally is high in vitamin A, C, and K, as well as folate, calcium, magnesium, and potassium.
Submerge whole lettuce head in fresh cold water, rinse thoroughly, then dry in a salad spinner until leaves are barely damp. Cover lettuce head with a paper towel to absorb moisture, and store in a half-sealed or perforated plastic bag in the refrigerator crisper for up to 5 days.
Despite being best known for use in raw salads, sandwiches, and wraps, lettuce is also a handy addition to soups, stir-fry, dal, juices/smoothies, and even pesto or chutney. Well-structured leaves with firm stems can be cooked on the grill, or used as cups to hold ground meat, dip, or other fillings.
Slice a firm lettuce variety (such as romaine or oak leaf) down the middle lengthwise, keeping the core intact. (If the lettuce head is very large, slice into quarters.) Brush lettuce sections with olive oil and crushed anchovy, if desired, and sprinkle all over with salt. Place cut side down on a hot grill for 2 to 3 minutes, pressing down to ensure a good sear. Flip and grill the opposite side for another 2 to 3 minutes. Remove from grill and top, if desired, with grated or shaved Parmesan cheese, halved cherry tomatoes, chunks of avocado, and garlic-soaked bread crumbs. Add additional olive oil, lemon juice, and salt, and pepper, and serve warm.
Slicing lettuce with a metal knife causes a reaction that encourages discoloration and wilting. To avoid this, tear lettuce leaves by hand rather than cutting them with a knife.