Rinse the fruits thoroughly and chill them in the fridge. Refrigerating after chopping will let out juices from the cut fruits making the custard runny.
Heat 2½ cups milk in a wide heavy bottom pan or pot. Add sugar and stir until it dissolves.
Meanwhile add custard powder to a small cup and stir it with ¼ cup milk (warm or at room temperature). The mixture has to be smooth without any lumps.
When the milk turns hot (not boiling), pour 2 tbsp of the custard mix to the hot milk. Whisk well to incorporate it with the milk.
Repeat adding another 2 tablespoons custard mixture to the milk and whisk well. This way incorporate all of the custard mixture to the milk in 3 batches, whisking after each addition.
You may taste test it at this stage and add more sugar if needed.
Keep stirring and cook on a low to medium heat until the custard turns thick. The custard must coat the back of the spoon well but must be yet of runny consistency. (check video)
Take it off the heat and whisk it well to make it super smooth. Cover immediately. Cool this completely and chill it in the fridge.
Whisk the custard well before serving. This ensures even and smooth fruit custard.
Peel and chop the fruits to bite size. Add them to serving bowl or individual serving cups.
Pour the custard over the fruits and gently mix. Serve fruit custard immediately.