Separate the eggs, beat the egg whites and cream separately from each other until stiff.
Melt the butter and chocolate in a double boiler.
Mix the egg yolks with 3 tablespoons of warm water and the sugar to a light, creamy mass. Fold in the melted chocolate-butter mixture, then carefully fold in the egg whites and cream with the spatula. Let solidify in the refrigerator (at least 2 hours).
In the meantime, remove the seeds from the pomegranate. Sprinkle on the mousse before serving.