Tasty Gluten Free Ham and Potato Breakfast Casserole

6 potatoes, peeled
4 tablespoons butter
1 cup shredded Cheddar cheese
1 cup shredded Gruyere cheese
1 onion, finely chopped
8 ounces ham
1 cup crème fraiche
8 eggs
1 tablespoon butter
Salt to taste
Pepper to taste

While preheating oven to 350 degrees, peel the potatoes and slice into fourths. Place them in a large pot and fill with enough water that all the pieces are covered. Bring potatoes to a boil and continue boiling for 7 to 10 minutes (you want the potatoes to be soft but not so soft that you can’t slice them).
While the potatoes are boiling, put 4 tablespoons butter in a 9x13 inch baking dish and melt in oven, then tip baking dish to make sure butter is distributed.
In a bowl, toss together the cheddar and gruyere cheese; set aside.
In a separate bowl, beat the crème fraiche and eggs together; set aside.
Once the potatoes are done, drain them and slice each piece in half.
Remove the baking dish from the oven and dump half the potatoes into the pan and layer as evenly as possible on the bottom of the dish. Sprinkle with salt and pepper and set aside. 
Take the remaining 1 tablespoon butter and place it in the same pot you boiled the potatoes in. Add the onion and sauté until tender, approximately 3 minutes.
While the onion is being sautéed, chop the ham. Mix the ham and onion together in the pot with the heat turned off, then layer half the mixture over the potatoes in the baking dish.
Scatter half the cheese mixture evenly over the ham-onion mixture, then put the remaining half ham-onion mixture on top, then use the remaining cheese mixture and sprinkle on top, then pour the egg mixture over all evenly.
Bake for 40 to 45 minutes or until golden brown.