Its name literally counts its own ingredients — 'nyergu' means nine, and the Nobgang village recipe uses exactly that many, right down to a sour, stream-side herb that lends a faint fishy note despite containing no fish at all.
Dried red chilies are roasted and pounded together with eight other ingredients, including a sour, stream-side plant called genche la, into a thick, fragrant paste. It's a specialty of Nobgang village in Punakha, traditionally packed in banana leaves and passed down as a closely guarded family recipe.