Knead the minced meat with a little salt and plenty of pepper, form small meatballs. Peel the potatoes and cut into soup-sized cubes (~ 1 cm). Tie the savory together with kitchen twine / parcel string. Pour the whole thing into 2 liters of water and bring to a boil. Add grained stock / stock cube to the amount of water.
As long as the potatoes and minced meat are cooking, use the butter and flour (plenty of heaped tablespoon) to make a light brown roux.
When the potatoes are almost done (approx. 20 min.), Add the drained beans, remove the savory, add roux and season with salt and plenty of pepper.