Make the instant mashed potatoes, adding the 2 generous cups of boiling water, according to package instructions. (You may substitute 2 cups of leftover mashed potatoes, if you have them.) Add in 3/4 cup shredded Cheddar cheese, 1/2 cup sour cream, 1/2 cup chopped green onion tops, and 5 oz. of tender chunk ham, cut into chunks. Add in any ham broth that may be in the can. Mix thoroughly, and then pour into a medium oven-proof baking dish that has been sprayed with cooking oil. Bake at 375 degrees for 25 minutes. Serve while hot. Your family will devour every bite of this!!!