In a skillet, fry potatoes in oil until tender, about 10-15 minutes.
Place in the bottom of four individual 16-oz baking dishes.
In skillet, scramble eggs in butter until done.
Spoon over potatoes.
Top with ham.
Pour 1/2 cup spaghetti sauce into each casserole; sprinkle with cheese
Preheat oven to 350°F.
Bake for 20 minutes or until hot and bubbly.