Makwaen or Sichuan pepper is a medium-sized tree, 5-10 meters tall, with thorns on its branches. The seeds turn brown when ripe and give off a fragrant aroma, similar to coriander seeds. Makwaen is a spice that is widely used from northern Thailand right up to southern China and during the reign of King Taksin the Great, growers in Nan sent Makwaen to the royal court as an offering. To this day, the most important source of Sichuan pepper cultivation is Na Muen District, Nan Province.

Although the spice has been in various local foods for decades, over the years Fried Chicken with Sichuan pepper has become a popular delicacy in Nan, possibly due to the chef from Nan who cooked the dish for Her Royal Highness Princess Maha Chakri Sirindhorn when she visited the province in 2009.

Subsequently, the Phu Fah Pattana Center in Nan Province encouraged the cultivation of Sichuan pepper. To restore forests and promote income for farmers, many northern dishes incorporate the herb in cooking such as Larb, Lu, Nam Prik, and curry. People in many northern provinces from Chiang Rai, Mae Hong Son, or Nan use Makwaen instead of black pepper by roasting the seeds on a low flame until fragrant, pounding them up and adding them to the food.