Steam the potatoes in their skins until tender. If you have any potatoes from the day before, even better as they are easier to slice. Scrape them and let them cool slightly until just warm.
Chop the onion finely.
Slice the potatoes thinly with a potato slicer or a vegetable knife. Place in a large bowl.
Add the onion and enough warm meat broth so that the potatoes are quite moist but not sitting in broth! and leave to soak for an hour.
Lastly add enough sunflower oil, vinegar, salt and pepper to taste. Again I can`t give exact quantities but I suggest that you start off with a couple of tablespoons of each of the oil and vinegar and then add more to taste.
Mix thoroughly. The potato salad should not be too dry, but quite moist.