Melt 2 tablespoons of butter or margarine in a deep skillet. Turn the heat to medium and add 2 large Idaho baking potatoes, peeled and cubed. Stir in 1 teaspoon salt. Cover, reduce the heat, and cook for 10 minutes, stirring occasionally. Add 1 small chopped onion, and cook for another 10 minutes, stirring occasionally. The potatoes and onions should be perfectly cooked by now. Next, add a 12 oz. can of corned beef, which has been cut or chunked into fairly equally-sized pieces. Stir together with the potato and onion mixture. Cover, and heat, just until the corned beef is heated through. Remove from the skillet, and place in a serving bowl. Serve while hot. This is as comforting as comfort food gets!!!