Chop bacon into 1 inch pieces. In a cast iron or other oven safe skillet, fry bacon till crisp. Drain on paper towels. In the same skillet, fry sausage till done and also drain on paper towels
Pour all but 3 tbsp of grease from pan. Add hash browns and onions. Salt and pepper to taste and spread evenly in pan. Put slices of butter on top of potato, onion mixture. Cover and cook 5-7 minutes over medium heat until potatoes are slightly browned on the bottom. DO NOT STIR.
Add spinach, mushrooms and blue cheese. Recover and cook another 3 minutes until spinach is steamed and cheese is starting to melt.
Add bacon, sausage and chopped ham. Mix eggs, half and half and nutmeg in a bowl. Pour over meat in skillet. Place tomatoes, cut side up, evenly around skillet. Top with parmesan and cheddar.
Cover and bake at 350 degrees for 10-12 minutes. Remove cover and bake another 5-7 minutes. Let set for a couple minutes. Cut into wedges to serve.