To prepare corned beef hash, gather 8 ounces of cooked corned beef, two potatoes, 4 tablespoons butter, one white onion and one bell pepper. Gather 2 tablespoons vegetable oil, salt and pepper to taste and four slices of cheddar cheese, if desired. Cook in a heavy skillet over high heat.
Dice the cooked corned beef into tiny pieces, then finely chop the green pepper and white onion, placing the cut meat and vegetables in separate bowls. Grate the potatoes (medium-size variety preferred), and place them in the bowl with the vegetables. Heat the vegetable oil in the skillet, and add the corned beef. Wait until the meat begins to brown and some of its fat renders out before adding the vegetables and potatoes.
Stir all the ingredients together in the skillet, then cook it for at least six more minutes without touching it again. This allows the proper crust to start forming on the bottom. After the six minutes pass, flip the hash over and cook until evenly browned on the opposite side. Season with salt and pepper, taste and adjust the seasoning if necessary. However, remember that prepared corned beef is typically salty already, so limiting the addition of excess salt is especially important. For full breakfast service, fry eggs in a separate pan, and place cheddar slices over the finished hash, allowing them to melt. Plate the hash with cheese and fried eggs on top.