In a large skillet over medium heat, melt butter. Add onion, 3/4 teaspoon salt, and 1/2 teaspoon pepper. Cook, stirring frequently, until onion is translucent, about 3 minutes.
Increase heat to medium-high, and add potatoes, water and garlic. Cover and cook for 6 minutes. remove the cover and continue cooking, stirring frequently, until no water remains and the potatoes are cooked through, about 6 minutes.
Remove pan from heat and using a spatula, mash approximately 1/8th of the potatoes. Stir mashed potatoes into the rest of the potatoes until just combined. Stir in corned beef and hot sauce. Spread hash into an even layer and press lightly. Return skillet to high heat and cook for 3 minutes.
Gently stir hash and continue to cook until potato edges are crispy and browned, about 3 minutes. Transfer to a platter and serve, serving extra hot sauce separately.
Potatoes: The recipe calls for Russet (baking) potatoes, but you can use Yukon Golds, or even sweet potatoes instead. The starchier the better, although this Corned Beef Hash recipe will work with any spud you have in the house.
Corned beef: Leftover (cooked) corned beef works well, as would smoked brisket, canned corned beef, or supermarket deli-style corned beef.
Yield: One batch of the recipe makes enough for 4 servings.
Storage: Keep the leftovers in the fridge and eat within the week.
Make ahead: Peel and cube the raw potatoes up to 24 hours in advance. Cover with water and chill in the refrigerator.
Sweet potatoes: Diced or shredded sweet potatoes make excellent hash, too.
Peppers: Along with the onions, add diced bell peppers of any color to the hash, if you have them handy.
Herbs: Fresh thyme, parsley, chives, rosemary; if you fresh herbs, chop and add one variety to the finished dish.
Eggs: Sunny-side up, poached, basted, or fried. Any way you like them; Corned Beef Hash tastes great with eggs.