Preheat oven to 325 degrees. In a large skillet, cook bacon and ham for 5 minutes, until done, stirring occasionally. Add chopped mushrooms and continue to cook for another 8 minutes, until mushrooms start to release some liquid.
Add chopped garlic and spinach. Stir and cook until the spinach is wilted, about 2 or 3 minutes. Set the skillet off the heat to cool a few minutes while the egg mixture is being prepared. In a large mixing bowl, beat eggs until well blended. Mix in the cheeses, one at a time. Add nutmeg, salt and pepper. Mix all together well.
Slowly add the cooled mushroom-spinach mixture to the eggs and cheese. Combine all of this well and pour into the 9 inch deep dish pie shell.
Place pie on a cookie sheet that is lined with foil and bake for 30 minutes at 325 degrees.
Remove from oven and cool 15-20 minutes before slicing.