Place raw corned beef brisket (approximately 2 pounds) in a slow cooker. Cover with Guinness Black Lager (2 - 3 bottles) and sprinkle with spice packet that is included in the corned beef package. Cook on high for 4 hours or until corned beef can be cut easily with a knife. Turn off heat and allow to cool. Cut corned beef into small cubes (cut off any fat) and set aside.

Melt butter in a large skillet. Add onion and sauté until onions are transparent and starting to brown. Add fingerling potatoes and spread evenly across the bottom of the skillet. Allow to cook over medium heat until potatoes are soft and lightly browned. Add more butter if needed to keep the potatoes from sticking to skillet. Sprinkle potatoes with freshly ground black pepper. Add cubes of corned beef and stir to combine all ingredients. Keep potato onion mixture warm while preparing eggs.

Prepare over-easy/medium or poached eggs to serve with corned beef hash and serve with your favorite type of toast.