Heat a large cast iron or other oven safe skillet over medium heat. Once heated, add the sausage. Cook, breaking up the sausage, until browned and cook through, about 7-10 minutes. Remove from the heat and let cool for 10 minutes.
In a medium bowl, whisk together the remaining ingredients, reserving ½ of the cheese to top if desired. Stir in the sausage. Pour the mixture into a cast iron skillet or other baking dish.
Transfer the skillet or dish to the oven and bake for about 35 minutes or until the center is set. Remove and let cool for 5 minutes before slicing and serving.
