In a large bowl combine the eggs, milk and cream then whisk until combined. Set aside.
In a 9 inch cast iron pan, layer the english muffins and ham in a spiral pattern. Pour over the custard mixture then allow to soak for 15-30 minutes.
Bake the english muffin casserole for 35-45 minutes, until the custard has cooked through and the top is golden brown.
While the casserole is baking, make the sauce. Over a double boiler, while the egg yolks constantly. Add the butter in a tablespoon at a time allowing to fully melt in between additions. Do this process quickly and continue to whisk constantly to keep the eggs from scrambling. Once all of the butter is incorporated you should have a light yellow thick rich hollandaise. Set aside.
Remove the casserole from the oven and top with the poached eggs. Generously over the sauce and serve.