This is what I've been drinking since my childhood. Tongpa. Strong bangchang in it. I'm from Gelephu. In every festival or celebration, we offer our guests with tongpa. In a big celebration like wedding where there will be a huge number of guests, you'll be offered tongpa in bamboo containers.
Adding hot water in the tongpa containers:
Stock of bangchang for tongpa:
This is how bangchang is prepared during wedding: