Faan-shyu yi-mai tong: Sweet potato and pearl barley soup
番薯: 4兩 (four tael sweet potato, cubed)。
片糖: 4兩 (four tael jaggery or gur)。
洋薏米: 1兩 (one tael pearl barley)。
薑: 1 片 (one thick slice ginger)。
清水: 4盃 (four cups water: 1斤10兩)。
Bring water, sugar, and ginger to a boil. Add the cubed sweet potato, cook for fifteen minutes.
Add the pearl barley, cook five minutes more.
Let cool slightly before serving.
[Good for the spleen and lungs, beneficial in cold weather.]
One tael (兩 leung) is one-and-a-third ounce, though nowadays metrified as fifty grammes. There are ten mace (錢 chien) in a tael, sixteen tael in a catty (斤 gan).
Two tablespoons of cornstarch are equivalent to one-and-a-half tael, ergo there are four teaspoons in one tael of cornstarch.
[From notations elsewhere: One cup sugar is 192 grammes, one tablespoon is 12 grammes, one teaspoon is four grammes. And one 兩 or 两 (leung) equals 37¾ grammes ~ 1.3 oz. So four tael sugar is the same as 4.3 oz., or approximately 150 grammes, 12½ tablespoons. Eh, ¾ cup.
Five tael would be exactly 190 grammes, or nearly sixteen tablespoons of sugar.]
Originally here: http://atthebackofthehill.blogspot.com/2013/11/sweet-times-two-cantonese-soup.html.