Clean the tripe, wash it and boil in water with a little salt. Once ready, cut it into small pieces.
In a pot, heat the butter and add the flour, which needs to redden just slightly.
Pour in the broth from the boiled tripe (strained beforehand) in a thin trickle, then add the tripe itself. Add the mashed garlic and black pepper and boil another 5 min. or so.
Thicken with the egg, beaten with the yoghurt.
Serve the soup warm.