Preheat the oven (electric cooker: 180 °C/circulating air: 150 C/gas: see manufacturer). Cut tomatoes and pickles into thin slices. Peel the onion and cut into rings. Cut the rolls in half crosswise and roast them in the oven (middle) for 5 minutes.
Heat some oil in two pans. In a frying pan, fry the slices of meat loaf on both sides for 10 minutes until brown. Alternatively use freshly baked Leberkäse.
Beat the eggs in the second pan and let them fry on a low heat for 2-3 minutes. Then turn and fry the fried eggs from the second side for 2-3 minutes as well. Season with salt and pepper.
Brush the cut surfaces of the rolls with mustard and spread the salad leaves on top. Layer 1 slice of meat loaf, 1 fried egg, tomatoes, cucumber and onion rings on each base. Place the lids on top and fix with wooden sticks.
Serve the burgers immediately. If you like, you can add potato wedges.