1.Melt butter in a skillet over medium-low heat. Saute onions in butter so long as soft. 2.In a large bowl, beat eggs. 3.Add milk, salt, ham, and all but 1/2 cup of cheese. 4.Pour egg mixture into a greased ovenproof 2 quart csserole. 5.Bake, uncovered, at 350 dgrs for 30 mins or so long as mixture is set. 6.Remove from oven and sprinkle with remaining cheese. Continue to bake so long as cheese melts.