Avoid cooking it, use it at the last minute with a fine grind.

Lai Chau is a province in northern Vietnam. This false pepper (zanthoxylum rhetsa) is harvested from a tree that grows spontaneously in mountain ranges. It's called "peak pepper", not because it grows in the mountains, but because it's found in the treetops. It's a close relative of Chinese Sichuan and Nepalese Timut, but much finer, more elegant and easier to use. Nor does it have the anaesthetic effect of Sichuan.