Romaine or cos lettuce is a variety of lettuce that grows in a tall head of sturdy dark green leaves with firm ribs down their centers. Unlike most lettuces, it is tolerant of heat.
Romaine lettuce is best suited for both raw and cooked applications such as braising, grilling, and lightly boiling. The leaves can be used fresh and torn for salads, or they can be used as a dipping vessel for sauces, dips, and fillings. They can also be layered on sandwiches, burgers, and wraps for added crunch.
To store a full head of lettuce, wrap it in a damp paper towel and put the head inside a plastic bag. Store in the refrigerator. If you're storing individual lettuce leaves, spin them dry after washing and place them in a lettuce keeper in the fridge. A container is best to avoid bruising and bacteria buildup.