Green Bean Sweet Potato Soup
This green bean sweet potato soup (绿豆番薯汤) is a Chinese dessert which is filling enough to be a “dessert meal” on its own due to the sweet potatoes. I learnt about this variant of green bean soup from my mum. She has been sending me daily photos of what she cooked or ate, even if they are repeats. So my phone has many, many pictures of this dessert because she has been cooking this dessert at least twice a week for the past year.
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If you are cutting down on refined sugar but still okay with natural sugars, you can opt not to sweeten the green bean soup with rock sugar, but instead let the natural sweetness of the sweet potatoes complement the unsweetened green bean soup.
The main ingredients are sweet potatoes (you can use any variety/coloured flesh or a mix), dried lotus nuts, dried orange peel, pandan leaves, rock sugar and of course, green beans (mung beans).
TWO METHODS OF MAKING THIS DESSERT
The first method is the easiest and most straight forward, which is to add the sweet potatoes to boil with the rest of the ingredients in the pot. This method is the most common way, and it is how my mum makes this dessert. Take out the sweet potatoes earlier (once they are ready) to avoid mushy and disintegrating bits in the soup.
The second method is to steam the sweet potatoes separately while the soup is simmering away. Pictured above is my tray of raw sweet potatoes before cooking. This is my preferred method as the steamed sweet potatoes retain their sweetness & firmness after cooking. The steaming juices collected in the steam tray afterwards can be poured back into the pot green bean soup.
This is my glass pot demonstrating both methods at the same time: the sweet potatoes simmering away in the pot, and the steamer rack above it where I steamed some sweet potatoes. I recommend the steaming method only if you have a steamer attachment on top of your pot or rice cooker, so that you can steam the food on the top tier while soup or rice is being cooked at the bottom. Otherwise, it will be an expense of effort and resources to steam the sweet potatoes separately.
Green Bean Sweet Potato Soup
The sweet potatoes can be boiled together with the rest of the ingredients in the pot, or steamed separately then added to the green bean soup.
If you are cutting down on refined sugar but okay with natural sugars, you can actually opt not to sweeten the green bean soup by omitting the rock sugar. Instead, let the natural sweetness of the sweet potatoes complement the unsweetened green bean soup.
Ingredients:
- 300g sweet potatoes (番薯) peeled & cut to large chunks; see cooking note below
- 150 grams green beans (aka mung beans/綠豆) soaked in hot water for 3 hours, rinsed and drained; see cooking note
- 4 pandan (screw pine) leaves tied into a knot
- 2 litres water top up whenever needed
- 3 small pieces dried orange/tangerine peel (陈皮)
- 15 dried lotus seeds (蓮子) optional; see cooking note
- 60 grams rock sugar (冰糖) to taste
Directions:
Method 1: Boil everything together
In a large soup pot, add all the ingredients except rock sugar. Bring to a boil. Reduce heat to a simmer, partially covered, for about 20-30 minutes (or until the beans are softened to liking), stirring the sides and bottom of the pot occasionally.Top up with hot water at any time if needed.
Take out the sweet potatoes once they are just softened (15-20 mins). Cooking the sweet potatoes for too long will result in them becoming mushy and disintegrating in the soup.
Method 2: Steam the sweet potatoes separately.
Follow method 1 above but steam the sweet potatoes separately for the same duration. When the sweet potatoes are done, pour the steaming juices back into the pot of green bean soup.
Regardless of whether you use method 1 or 2 above, add rock sugar to taste only during the last 5 minutes of simmering and stir until the sugar is dissolved. Discard orange peel slices and pandan leaves. Serve the green bean soup either at room temperature or chilled with chunks of sweet potato in each bowl.
Cooking Note(s):
- Sweet Potatoes. You can use any variety and colour (orange, yellow or purple flesh), or a mix.
- Soaked green beans aid digestion by reducing gas, shortens the cooking time & helps to clean the beans. If you don’t have the practice of soaking the beans before cooking, feel free to skip this step and add a few more minutes to cook the beans to your preferred softness.
- Lotus seed. Try to buy dried lotus seeds without the green germ in the middle. Otherwise, you need to halve each seed to extract the green germ which is bitter tasting. In place of dried lotus seed, you can also use instant gingko nuts (either vacuum packed or canned ones).
- Sago. Refer to this tutorial for cooking sago, then add them to the bowl of green bean soup during serving.