Classic use of your leftover corned beef (or any leftover beef you may have). You can vary the proportions according to personal taste and what you have on hand. One way to start is with roughly equal volumes of meat, potato and onion.
1 1/2 cups cooked meat
1 - 2 medium raw cubed potatoes, with or without skins
1 medium size onion, diced
1 stalk celery finely chopped (optional, or if you don't have celery seed or salt)
1 - 2 TBSP vegetable oil, like canola
Salt (careful, corned beef is already salty), pepper, celery seed or 1/2 tsp dried herbs
Food processor or meat grinder, or good chopping knife and patience, large sauté pan.
COMBINE ingredients and process to coarse mix:
TURN these ingredients into a hot, well-greased skillet.
COOK the hash over medium heat, turning occasionally until onion is transparent and hash starts to brown.
PAT DOWN to form a cake, continue until a crust forms on the bottom, turn it and brown the other side (you can also brown the top under oven broiler).
SERVE with catsup or tomato sauce - top with fried or poached egg.