You can peel your potatoes or leave the skins. Cut potatoes into small cubes.
In a large bowl combine ham, onion and potatoes. Lightly toss together.
In a small bowl combine butter, mustard, Parmesan cheese, Worcestershire, horseradish and pepper. Pour over potato mixture and lightly combine.
Spread into a greased 13x9 baking dish.
Top with shredded cheeses.
Bake uncovered for 25 min. Remove from oven and with the back of a spoon make 6 little wells. Crack an egg into each well and return to oven for 12 more minutes.