Ginger is not allowed in boiled rock sugar water.
Stewed Sydney with rock sugar:
1. Wash, peel and cut pears.
2. Add a small amount of water to the pot. Just add pears and boil them.
3. Then add rock sugar, change to medium heat, and simmer for 20 minutes after the rock sugar is completely melted.
4. Turn off the fire and stew 10 minutes or so.