Grease the inside of four oven-safe individual size casserole dishes or ramekins with the butter.

Rinse the spinach and wilt it over medium-high heat in a large skillet. Remove from the pan and put in a strainer. Use the back of a bowl or the back of a spatula to press out as much of the water as you can. This step can be done the night before, but you'll need to add a few minutes of cooking time if you use cold spinach.

Divide the ham and layer it inside each baking dish, placing the ham so that it comes up the inside of each dish.

Top with 1/4 of the spinach, then add the egg. Drizzle with 3 tbsp of heavy cream, and 1 tbsp of Parmesan cheese. Add a few grinds of pepper.

Put the casserole dishes onto a baking tray and bake in a pre-heated 375-F oven for about 12-15 minutes. Put under the broiler for the last minute or two to cook the top of the egg. Remove when the egg has reached your desired doneness.