Cook corned beef according to package instructions. Let cool, trim excess fat and hand shred.
Boil baby red potato in salted water until fork-tender, set aside.
In large skillet, heat butter over medium heat, sauté onion and pepper until soft (3 – 5 minutes), increase heat to medium-high, add cooked red potato and crush with the back of a spoon, continue sautéing until lightly brown, add shredded corned beef and heat through*.
*To achieve a nice crust after hash is heated through - continue cooking undisturbed for additional 5 minutes