Generally speaking, hash is made from leftover meat and potatoes. It's a fine way of repurposing food in the fridge. That said, hash is good enough—and comforting enough—to be made from scratch for enjoyment's sake.
This version combines tender, whiskey-marinated brisket with sweet potatoes and Serrano peppers for a blast of sweet heat. A touch of maple syrup and dash of Worcestershire tie the whole thing together.
If you're opposed to making the meat just because, feel free to substitute leftover chopped up beef short ribs, steak, or roast. It'd work with run-of-the-mill potatoes, too, so go ahead and use Idahos or Yukon Golds if that's what you've got. Just know the flavor profile will change. Serve it alongside a gently poached or lightly fried egg.
Note: I opted to cook the potatoes in a two-part process, first in the oven and then in the pan. It speeds up the process overall, while helping to keep their shape intact. If you want to cook the potatoes entirely in the pan, feel free to; just give them an additional 15 minutes or so cooking time.