1. Steam with water. Put the cooked cold rice dumplings in boiling water and heat them for 8~ 10 minutes, or steam them in water.
2. Heat the zongzi in the microwave oven, put it in the steamer, select the quick heat button or the big fire button, and heat it for 5 minutes.
3. Fry in a frying pan. Add an appropriate amount of cooking oil to a frying pan (preferably a non-stick pan), heat it, then add thick zongzi slices, and fry the zongzi with slow fire until both sides are golden.