The word endive is used to refer to the leafy part of any of a variety of plants in the chicory family. The three main types you will see in cooking are curly endive (frisée), broad-leaf endive (escarole) and Belgian endive. They each have a different taste and levels of bitterness and can be used in different ways. Here are the basics about these three types.
Curly Endive - Frisée
Curly endive has the scientific name of Cichorium endivia var crispum and is sometimes called frisée or chicory.
It is not the compact rocket-shaped bulb of Belgian endive, but instead is a bushy head of curly greens with leaves of a lacy texture. The flavor can be somewhat bitter, with the bitterness more intense in the leaves that are a darker shade of green. It is often used in salads to add texture as well as the bitterness of this green. While some people like this in their salads, others do not.
Broad-leaved Endive - Escarole
Broad-leaved endive is of the same genus and species as curly endive, but a different variant. It is Cichorium endivia var latifolia and is sometimes called escarole. It is less bitter and the inner, lighter colored leaves can be used for raw and in salads. The outer, darker leaves are more bitter and can be tougher, but are very good to use chopped in soup and cooked dishes.
Belgian endive is a form of common chicory, Cichorium intybus, a different species from the other two endives Belgian endive is a small, cylindrical head of lettuce with pale yellow leaves with slightly curly edges.
Some describe it as rocket-shaped. It is more bitter and it is grown just beneath the soil in dark rooms, much like mushrooms, to keep it pale and preserve its delicate flavor.
Belgian endive can be used in salads and can also be braised or baked as a side dish. The leaves can be separated and used as the edible dish for small appetizers or used as dippers.
The compact heads of endive can be brushed with a vinaigrette and grilled, a good side dish for grilled fish.
A red-hued variety of Belgian endive is known as red endive or radicchio. Radicchio is the same species as Belgian endive but has red or variegated leaves. It is similar in being bitter and is often used in salads to add color and flavor.
Dealing with the Bitterness of Endive
After a few experiences with a bitter radicchio or frisée salad, some people avoid endive. However, the bitterness is lessened with cooking and it should not stop people from using it in soups and other cooked dishes. Blanching the greens will also reduce the bitterness, but may not be desired if you intend to use them in a salad. You can also soak the leaves cold water for an hour and rinse well to remove some of the bitterness.
Pronunciation: on-DEEVE, en-DEEVE. There is a statement by the California Endive Farms that curly and broad-leaved endive is pronounced en-dive, while Belgian endive has the on-deev pronunciation.