In a bowl, mix the egg whites and the sugar. Cook them in a water bath. Cook on low heat so that the water will not boil.
Keep mixing the mixture until the sugar crystals are completely dissolved. In order to know whether the meringue is ready, there are 2 things you can do: take its temperature with a thermometer, which should reach a temperature between 140 and 160 degrees, or rub a little bit of the mixture with your index finger and thumb. If you don’t feel the sugar crystals, it’s done.
Remove the mixture from the water bath and beat it in the mixer on high speed, until it forms firm peaks.