Radicchio

Culinary uses

In Italy, where the vegetable is quite popular, it is usually eaten grilled in olive oil, or mixed into dishes such as risotto: in the United States it is gaining in popularity but is more often eaten raw in salads. As with all chicories, if grown correctly its roots can be used to mix with coffee. It can also be served with pasta, in strudel, as a poultry stuffing, or as part of a tapenade.

Use and toxicity
According to traditional folklore, long-term use of chicory as a coffee substitute may damage human retinal tissue, with dimming of vision over time and other long term effects. Modern scientific literature contains little or no evidence to support or refute this claim. Root chicory contains volatile oils similar to those found in plants in the related genus Tanacetum which includes Tansy, and is likewise effective at eliminating intestinal worms. All parts of the plant contain these volatile oils, with the majority of the toxic components concentrated in the plants root.
Chicory is well known for its toxicity to internal parasites. Studies indicate that ingestion of chicory by farm animals results in reduction of worm burdens, which has prompted its widespread use as a forage supplement. There are only a few major companies active in research, development, and production of chicory varieties and selections. Most of them are in New Zealand.

Radicchio is easy to grow but performs best in a spring (USDA Zone 8 and above) and fall (everywhere) gardens. It prefers more frequent but not deep watering, the amount of water varying based on soil type. Infrequent watering will lead to a more bitter tasting leaf. However, for fall crops the flavor is changed predominantly by the onset of cold weather (the colder, the mellower), which also initiates the heading and reddening process in traditional varieties. There are newer, self-heading varieties whose taste is not yet as good as a traditional variety which has matured through several frosts or freezes (E.g., Alouette). Radicchio matures in approximately three months. However, it can be made to stand through a UK or West European winter, and the head will regenerate if cut off carefully above ground level, so long as the plant is protected against severe frost. A light-excluding cover, e.g. an inverted pot, may be used during the latter phases of growth to produce leaves with a more pronounced colour contrast, simultaneously protecting against frost and cold winds. Traditionally in the UK, the first cutting of all chicory heads was simply thrown away, and the tender, forced, second head was for the table. However, improved varieties of radicchio, e.g. Rosso di Verona, and generally milder winters allow the West European cultivator to harvest two or more crops from a single planting. If the head is cut off complete, just above the root, a small, new head will grow, especially if minimal frost protection is given. This process can be repeated a number of times.

Radicchio is a leaf chicory (Cichorium intybus, Asteraceae), sometimes known as Italian chicory and is a perennial. It is grown as a leaf vegetable which usually has white-veined red leaves. It has a bitter and spicy taste, which mellows when it is grilled or roasted.