Put half the milk in a pan with sugar and let it boil over low heat. Then add a finger (approximately) of milk and cornstarch and stir well. Add this mixture as soon as the milk boils, then lower the heat, and stir until it thickens.
Chop the bananas in another pan with sugar and leave on low heat until caramelized. Turn off the fire .
Add the cream in dessert pots and add the sliced bananas.