Bring the milk to the boil in a saucepan together with the fresh peach leaves. Let it infuse for 5 minutes over a very gentle heat.
Meanwhile separate the eggs into two bowls (the one for the whites should be large and very clean) keeping the whites on one side, but not in the refrigerator. Add the sugar to the yolks and whisk well until light and pale. Pour the milk through the sieve on to the egg yolks whisking all the time.
Pour the mixture back into the saucepan and heat very gently, stirring with a wooden spoon until the custard starts to thicken. To tell when it is thick enough press your finger lightly on the back of the wooden spoon – if it leaves a trace in the coating of custard, it is ready. Pour the custard into a cold bowl and whisk it from time to time as it cools. You must never let it come to the boil or it will start to curdle. If this happens whisk it energetically or put it into a bottle and give it a really good shake.
Put 2litres of water, a vanilla pod and a pinch of salt into a fairly large saucepan and bring to the boil.
Beat the egg whites together with a pinch of salt. When they have become a soft snow add 30g (1oz) of sugar and continue beating to a very firm snow. Using a tablespoon, scoop the meringue into large balls. Turn down the heat under the saucepan of boiling water and put in the balls of meringue; allow them to poach gently for 5 minutes, turning them over half-way through the cooking. Then take them out carefully with a skimmer and put them to drain on a folded teatowel.
Pour the cold custard into a nice bowl and put the egg whites on top. Keep in a cool place. Crush the praline in a cloth with a rolling-pin or bottle. Just before serving sprinkle the praline over the egg whites and serve.