Preheat the oven to 300°F (150°C).
Put the sugar and water in a pot on the medium heat until the sugar starts turning golden.
Quickly add the hot water and stir (Be careful when you pour hot water into caramel sauce. You have to avoid the hot sauce splashing and burning your hand)
Pour the caramel evenly into the custard cups, and put them into a fridge. (The caramel sauce needs to harden completely before you pour in the flan mixture.)
Add the eggs into a bowl, lightly beat the eggs with a balloon whisk but not foamy, and place aside.
Add the milk and castor sugar in a pot. Heat and stir until all the sugar is dissolved, then Remove from the heat.
Pour the milk mixture into the eggs slowly and stirring constantly.
Pour the egg mixture through a sieve two times into a container.
Take the custard cups out of the fridge, and fill the custard cups with the egg mixture.
Prepare the water bath with a deep tray. Place the custard cups in the tray and pour hot water into the tray.
Bake in the preheated oven 300°F (150°C) for 25~30 mins.
Remove from the oven, let the cups cool down completely. And place them into the fridge for a 3~4 hours.
Using the tip of a knife to scrape the side of the cup, place a plate on top of the cup and turn it upside down. Serve the caramel custard pudding on a plate.
Finish and enjoy your time.
