Boil diced potatoes in salted water until just shy of fork-tender. Drain well.
Mix the drained potatoes with the chopped corned beef. Set aside.
In a large skillet, melt the butter over medium heat. Add onions and fry until translucent, about 5 minutes.
Add the potato and beef mixture to the skillet along with the heated beef broth.
Cover with a lid and cook for 14–16 minutes, or until a deep golden-brown crust has formed on the bottom. Resist the urge to stir.
Season with salt and pepper. Invert onto a platter or serve directly from the skillet. Top with fresh parsley and a fried or poached egg.