It looks like lettuce, but this leafy veggie can be served hot or cold.
Escarole, a variety of endive (another bitter-tasting green), was first grown nearly 5,000 years ago and used by the Egyptians, Greeks and Romans as a salad vegetable. It was also considered medicinal, thought to help with digestion. Escarole looks very much like butterhead lettuce but the leaves are fleshier, with jagged, pointy edges versus the softer ruffle of lettuce. It has a nutty, somewhat bitter taste that becomes progressively mellower towards the inner leaves. This green makes a flavorful, textural addition to salads and sandwiches as well as hot dishes; braising in particular brings out the best in its flavor. It is an excellent source of folate, vitamins A and C, iron, magnesium, potassium, thiamin, and riboflavin.
Escarole should be stored in the refrigerator and used within a week.