For the Gundel-style pancakes, stir milk, eggs, flour, sugar and salt into a smooth batter, let rest for an hour. Just before baking, stir the soda water into the batter.
Heat butter in a frying pan and bake thin pancakes, keep warm. For the filling, briefly boil the whipped cream and add the ingredients. Let simmer on low heat for about 1 minute. Put 1 tablespoon of filling on each pancake and roll up.
Melt the chocolate in the warmed milk. First add yolks, then butter, cocoa, sugar and rum and stir until smooth. Pour the sauce over the pancakes Gundel-Art.