In a large frying pan add butter and melt on medium heat then add 3 tablespoons of corned beef juice; add 1/2 onion diced and diced corned beef. Simmer on low for 5 minutes. Add potato mixture and paprika to the pan. Bump the heat up to high and cook for 5 minutes (keeping the potato mixture on top). Mix the potatoes with the meat and flip over. Smash down with a spatula and cook for an additional 5 minutes. Add the remaining one tablespoon of corned beef juice and more butter if needed. Cook for 5 minutes more (the hash should be crispy but not burnt). Serve with or without a fried egg on top. The option is yours but most importantly, enjoy!