100 grams red beans (may also use Japanese azuki beans) soaked overnight, rinsed and drained
2 pandan (screw pine) leaves dried ends cut, tied in a knot
1.7 litres water
70 grams rock sugar to taste
10 grams (about 3 pieces) dried orange (tangerine) peel
80 grams canned or vacuum-packed lotus seeds or ginkgo nuts optional
50 grams (1/3 cup) small sago (small tapioca pearls)

Bring a small pot of water to boil. Add sago and simmer for 10 minutes. Turn off the stove, cover the pot with lid and let the sago continue to cook on its own for another 10 minutes, until all the sago turns translucent. Run the cooked sago through a fine sieve and running water to remove excess starch. Set aside. Check out this step-by-step photo tutorial for preparing sago.
In a bigger soup pot, add red beans, 1.7 litres water, dried orange peel and pandan leaves. Bring to a boil.
Add lotus seeds/gingko nuts and reduce heat to a simmer, partially covered, for about 50 minutes (or until the beans are soft), stirring the sides and bottom of the pot occasionally. Top up with hot water at any time if necessary.
Stir in rock sugar (to taste) until the sugar is dissolved. Discard orange peel slices and pandan leaves. Add the cooked sago prepared in step 1 to the red bean soup. Serve warmed or chilled.