Jin dou spare ribs recipe

Ingredients

• 500 g spare ribs, cut into pieces
• 1 tablespoon oyster sauce
• 1 teaspoon sugar
• 1 teaspoon salt
• 1 teaspoon sesame oil
• 1 egg
• 2 tbsp plain flour
• 1 tablespoon corn flour
• 1 tablespoon custard powder
• 3 tablespoons water
• 50 ml black vinegar
• 1 tablespoon worcestershire sauce
• 2 1/2 tablespoon tomato sauce
• 2 1/2 tablespoon plum sauce
• 1 tablespoon sugar
• 1/2 teaspoon five spice powder
• 50 ml water
• some corn flour water, for thickening (1 tablespoon cornflour mix with 100 ml water)