Cantonese eat tong-sui/sweet soup all year round. Just like savoury soups, Cantonese cook tong-sui according to the season and body condition. In cold days, I prefer tong-sui in a thick consistence, black sesame soup is one of those thick sweet soups. Besides, almond soup and peanut soup are also classic Cantonese tong-sui.
The concept of healthy eating has been popularized in Cantonese regions for centuries. Black sesame is healthy or even considered super food in recent years. Traditional Chinese medicine has believed sesame, especially black sesame, can help to replenish blood and nourish hair.
In the old days, people would grate sesame seeds with long-grain rice using stone mill. Few dessert bistros would do it in this method nowadays. Read more about Tong-sui in my previous post, .Autumn Tong-sui, snow fungus, pear and sea coconut Cantonese sweet soup
In this homemade version, a helpful electric food processer would be good enough to blend sesame seeds smoothly and silky. Instead of using rice, rice flour is even quicker and easier. Some people would like to add some sweet rice dumplings in the soup but I prefer those small ones without fillings. Black sesame soup should be served hot. It would turn thicker when cool down so reheat it before serving.
Black sesame seeds, 1 cup
White sesame seeds, half cup
Rice flour, 4tbsp;
Glutinous rice flour, half cup;
Water, 4 cups