andaliman

North Sumatra highlands (Batak country); Zanthoxylum acanthopodium, a citrus-electric relative of szechuan pepper that grows from the Himalaya through south China into west Malesia, and is cooked with almost nowhere but here

Held almost entirely within Batak cuisine: saksang, arsik, and the spice pastes of Toba and Karo kitchens; nearly absent from the export economy and from most Indonesian restaurant menus outside Sumatra, despite a range that reaches Nepal

Andaliman is Sumatra insisting on its own name: the numbing, mandarin-bright pepper of Batak cooking, ground into saksang and arsik around Lake Toba. The plant itself is not rare. Its range runs from the Himalaya through southwest China into peninsular Malaysia and Sumatra, which is a very large part of Asia. What is rare is anyone outside Batak country cooking with it. Indonesian food abroad usually means Javanese food, and the label 'Indonesian cuisine' is a nation-sized sheet thrown over hundreds of distinct food cultures. Andaliman does not appear in that version at all, and scarcity cannot be the reason, because a pepper growing across five countries is not hard to find. This means the pepper is a test: any account of the archipelago that includes it has bothered to look past Java.