Recently, I drank a kind of tea in the restaurant, which tasted like biscuits but not barley tea. It was delicious.
Generally, if the tea you drink in a restaurant tastes like biscuits, not barley tea, there is a possibility that it is buckwheat tea. When you say biscuits, it should be a bit like maltose or caramel, with a sweet smell, because the aroma of buckwheat tea is more in line with what you described, and the price is closer to the public taste of operating restaurants. So the comprehensive judgment should be buckwheat tea.