Sweat the onions. Add the beans with the stock, add the stock cubes and bring to the boil briefly. Mix the starch with a little cold water (or shake it in a small shaker) and thicken the stew with it.
Stir in tomato paste, add the drained spaetzle and season well. Finally, heat the meatloaf in a stew.
Also tastes great as a vegetarian stew without meatballs.