1 - Sauté the onions: Heat butter in a large skillet (preferably cast iron) on medium heat.

2 - Add the onion and cook a few minutes, until translucent.

3 - Add the potatoes and corned beef: Mix in the chopped corned beef and potatoes.

4 - Spread out evenly over the pan.

5 - Increase the heat to high or medium high and press down on the mixture with a metal spatula.