Peel the onion and cut into small cubes, sauté them in oil or butter. Deglaze the beans with the liquid and add the beans. Add salt, pepper, savory and the paprika powder. It is better to season a little and season later. Let the beans simmer for about 10 minutes. Make a roux with the broth, butter and flour, add to the beans and bring to the boil briefly. Turn off the stove and stir in the crème fraîche, season again to taste.