Preheat oven to 350F degrees.
In a medium-size skillet over medium heat, cook breakfast sausage fully, breaking into crumbles.
At the same time, in a large-size well-greased skillet, cook potatoes until browned.
In a well-greased pie pan, press potatoes into a firm crust at the bottom.
Press sausage in the pan on top of the hash browns.
In a small bowl, whisk together garlic, onion, eggs, and milk/egg whites. Pour evenly over sausage in the pie pan.
Top with cheese, if desired.
Bake for 40 minutes and serve hot.