Caramel

1. Dissolve the sugar in the water in a small saucepan and cook to a pale caramel color. Ideally, place the pan on some ice cubes to stop the cooking.
2. Pour the still liquid caramel into the ramekins, swirling to coat the bottom and sides.

Custard

1. In a saucepan, heat the milk with the vanilla bean.
2. Beat the eggs with the sugar.
3. Mix half the hot milk into the egg-sugar mixture without whisking (i.e., without creating a foam.)
4. Pour the mixture (step 3) into the remaining milk; check the temperature - it should be slightly hotter than lukewarm. Otherwise, heat it for a few moments over low heat without boiling. Strain if necessary for a smooth texture.
5. Pour the mixture into the caramel-lined ramekins. Place the ramekins into a pan and add boiling water to reach 1/3 of the way up the ramekins. You can also cook it directly in the oven.
6. Cook in a 150° C (300° F) oven for about 1 hour (40 minutes if not using the water bath). The custard must not boil. Check the doneness with the tip of a knife, as you would for a cake. Chill. Unmold just before serving.