Place minced onion in a bowl and pour hot broth over it, then add vinegar, salt, pepper, and sugar
Add the warm, finely diced potatoes and gently combine
Let this mixture cool completely
When cooled, fold in Fleischsalat, mayonnaise, diced apple and chopped eggs
Taste and adjust seasoning - the salad should be creamy, slightly tangy and perfectly seasoned
Refrigerate for a few hours or overnight before serving cold
