Belgian endive is an extremely pale yellow, almost white, tightly packed head of leaves as long as a hand. It is grown in the dark, which stops chlorophyll from developing and keeps the leaves white. Look for tightly enveloped leaves, the palest of yellow coloring with no green at all, and fresh, moist cut ends.
Since they are "forced" to grow in artificial conditions, Belgian endive are available year-round. Their traditional season (when grown in fields and covered with sand to keep out the light), like that of all chicories, is late fall and winter.
Belgian endive can be chopped and added to salads, separated into leaves and used as serving vessels for dips and spreads, or slowly cooked over low heat as in Braised Belgian Endive.
Red Belgian Endive
"Red Belgian endive" is technically a small, forced radicchio. These plants are all so similar, however, that these tiny oblong radicchio heads can be used interchangeably with traditional white Belgian endive. Be warned that it does not keep its brilliant color when cooked but turns a vaguely blue-ish gray purple shade.
While it is delicious cooked, this tiny version of radicchio is at its best when used in salads, added to crudites platters, or used as the base for canapes.
Curly Endive (a.k.a. Frisee)
Unlike Belgian endive, with its tightly closed heads, curly endive looks a bit like an untended lion's mane. Curly endive, also known as frisée, has a slightly shorter shelf life than other chicories and keeps best if treated like lettuces leaves, washed and stored rolled in paper towels.
Curly endive is most commonly used in salads, like Curly Endive With Poached Egg, but is tasty when quickly sauteed and drizzled with a bit of strong vinegar, such as sherry or balsamic.
Escarole looks somewhat like a large, sturdy head of Boston lettuce. It has a similar crunch, too, but a much more assertive flavor.
Escarole is great torn into bite-size pieces for a salad and stands up well to bold dressings. Weather in salads or cooked, escarole pairs particularly well with egg, as in Chickpea & Escarole Stew. Also try it grilled or broiled for a powerful accompaniment to roasted or grilled meats.
Radicchio is a brilliantly magenta colored set of leaves. The most commonly available radicchio is Chioggia radicchio that looks like a small cabbage, and, in fact, resembles a looser-leafed and whiter-ribbed version of red cabbage.
Radicchio is sometimes sliced and added to salads (like this Radicchio Salad With Green Olive Dressing), like all chicories, but really shines when cooked a bit. Halved and brushed with oil, it's great on the grill. It pairs particularly well with olives, blue cheese, apples, and walnuts.