01 -
Boil peeled and diced russet potatoes in salted water until fork tender, approximately 5 to 10 minutes. Drain thoroughly.
02 -
Heat 4 tablespoons of butter in a large skillet over medium heat. Add potatoes, diced onions, kosher salt, and black pepper. Cook while stirring occasionally until onions soften and mixture begins to brown, about 8 to 10 minutes.
03 -
Add chopped corned beef, garlic powder, and onion powder to the skillet. Stir to combine evenly.
04 -
Press the mixture firmly into an even layer using the back of a spatula. Cook undisturbed for 3 to 5 minutes until a golden crust forms on the bottom. Scrape and flip the hash to transfer the crusted side upwards. Add remaining 2 tablespoons of butter and mix through.
05 -
Press the hash down again into an even layer and cook for another 3 to 5 minutes to brown the bottom. Repeat this process two more times or until desired browning is achieved. Garnish with parsley if desired and serve immediately.