1. Separately soak dried oysters, dried mushrooms and bean curd sticks.
2. Dice soaked oysters and mushrooms. Cut bean curd sticks in 2-inch lengths. Mash red bean cheese.
3. Heat oil. Add salt, then red bean cheese, and stir-fry 1 minute. Stir in oysters, mushrooms and bean curd.
4. Add stock, sugar and remaining oil. Bring quickly to a boil, stirring gently. Then simmer, covered, 45 minutes, stirring occasionally.
5. Blend cornstarch and cold water to a paste; then stir in to thicken, and serve.