2 medium-sized onions, diced
3 cups diced boiled potatoes (3 to 4 large potatoes)
3 cups diced cooked corned beef (about 1 pound)
In a large skillet, melt butter over medium-high heat and saute onions 3 to 4 minutes, or until tender.
Add diced potatoes, and cook 10 to 12 minutes, stirring occasionally. Add corned beef, and cook 5 to 6 minutes, until heated through.
*You can substitute any baked, boiled or roasted cooked potatoes, if you'd like.