Cut the beef and onions into cubes, they can be a little coarser. Fry the meat in the butter until it is nice and brown. Then add the onions and continue frying on a medium heat. When the onions are translucent, continue cooking on a low heat. Now add the bay leaves, the cloves, the sugar, the vinegar and the bouillon, salt and pepper. Put the lid on the pan and let it simmer for 2 hours at low heat. At the end of the cooking time, remove the bay leaves and cloves and, if necessary, thicken with cornstarch.