Prickly ash or ‘makhwaen’. A North Thai spice discovery

Discovering Makhwaen or Citrus prickly ash                                

A couple of days ago I was given a very simple, very aromatic soup which has haunted my taste buds ever since. 
The ingredients seemed too simple to have such a tantalising taste and depth of flavour and I was left scratching my head.

The soup was local catfish, fresh from the pond simmered with onion, tomato, garlic, chilli and water.
It was very simply finished with culantro (sawtooth or broad leaf coriander)

There was a secret ingredient – dried flower buds from a local tree which are simply toasted, pounded and added into the soup a moment before serving. The taste is incredible. 
I can describe it as heady, slightly woody, aromatic, intoxicating and so deep and rich – this is my ingredient discovery of the decade. It's related to Sichuan pepper, but the sub species is called  "Zanthoxylum limonella Alato" or Makhwaen in Thai

Prickly ash adds a point of difference to any menu.
It's a regional specialty from Chiang Rai, the North of Thailand & Laos but not at all common or available in Bangkok, or most other parts of Thailand

Prickly ash can be used as an interesting, mostly unknown spice for chefs, bakers and creative culinarians. 
As well as the soup application, I've used this in breads, pizza bases, dips and or infused into a jus for beef, venison, lamb, kangaroo and game meats. 

It makes a great infusion in salt, and an excellent compound butter for grills

In North Thailand it's used mainly in "Gaeng" style soup broths with fish, chicken or beef, or in raw fish laab, which is a tad chunkier and more "rustic" than the now popular Isaan version.

It is so EASY to use too. Pound or grind briefly – and add to the soup last minute before serving. Easy and foolproof.
This is a spice that deserves to be discovered by innovative chefs.

This is a contender for the spice of the decade. Here is a little more detail, and some photos of "muh-kan" – both dried, and on the tree.

Dried – this variety has small seeds that look like tiny star anise pods or chunky Schezuan pepper..

Bagged up into domestic quantity. Enough to use 10-15 times

These are the 'flowers' fresh on the tree. You have to wait until they start to shrivel and dry – then harvest them, dry them and store properly for use.

The spiky trunk of the tree. They're not all this tall – and I'd hate to have to climb one…OR come down.
It would be like making love to a porcupine, or riding a runaway cactus. If harvesting yourself – go for a shorter, bushier tree like the one below.

This photo gives a better idea of what the leaves of the tree actually look like.

There's nothing complex about it, except for the depth of the flavour.
This is fantastic infused through a pure, well made jus, over game meat or high quality beef, accompanied by a glass of exceptional Shiraz.

***Many thanks to Robyn from eatingasia blog, and my friend Darr from Bangkok for assisting with identification, English name and a substitute for this amazing spice. 
Robyn suggests substituting with Schezuan pepper pounded with a little orange zest. It could be almost awesome.