Posted: 05/12/2015 at 12:57
I found the following on Google:-
Growing Belgian endive. To produce a blanched head, dig up the chicory root and cut off the top about 2 inches above the crown or top of the root. In a cool, humid place such as an outdoor pit, cold frame, or root cellar, bury the root to force it to produce a blanched sprout: first, cut off the root tip so that the root is 6 to 8 inches long; set the root upright at a slight angle in a box, pot, or other container filled with fine sand or a mix of sand and peat moss just covering the top; water thoroughly, and keep at a temperature of 60° to 70°F. The tight, pale-green head will develop in 3 to 4 weeks.
Have a google yourself for more info.