Preheat oven to 400 degrees. Place one tablespoon butter in cast iron skillet and melt in oven.
Put eggs, flour, milk, salt, and pepper into a blender and mix until smooth. Pull skillet from oven once butter has melted and brush butter on sides of skillet. Pour egg mixture into it and top with scattered ham, cheese, thyme, and sage.
Place in oven and cook for 20-25 minutes or until golden brown and cooked through.