Peel the potatoes and cut into not-too-thick slices. Place in a bowl of cold water to remove the starch.
Heat a large pan over medium-high heat and add the oil. Drain the potatoes and slide them into the hot pan while still dripping wet. Close the lid immediately and cook covered for 10-15 minutes. Open the lid, stir the potatoes, and distribute the bacon, onions, and caraway seeds over them without stirring. Close the lid again, reduce the heat to medium if browning too strongly, and cook for 5 more minutes.
While the potatoes are cooking in step 2, cut the meat loaf into slices similar to the potatoes. When step 2 is complete, open the lid, stir everything together, add the meat loaf slices, marjoram, and salt. Continue frying uncovered over medium heat, stirring occasionally, until browned. Stir in the parsley, gherkins, and black pepper.
In a separate pan over medium heat, fry the 4 eggs in butter.
Divide the Gröstl among preheated plates and top each with a fried egg, or serve directly from the pan.