Preheat the oven to 400 degrees F. Grease a 9-inch deep-dish pie dish with butter. Place the frozen tater tots in the prepared pie plate. Spread out evenly. Bake for 15 minutes in the preheated oven.
When finished cooking, mash the tater tots into an even layer so they cover the bottom and sides of the pie dish.
Reduce the oven temperature to 350 degrees F.
Meanwhile, fully cook and crumble the breakfast sausage in a skillet over medium to medium-high heat. Remove from the heat and allow to cool down a bit.
In a large bowl, whisk together the eggs, cottage cheese, salt, and pepper. Stir in the mozzarella cheese and the slightly cooled-down sausage. Stir to combine. Pour this mixture evenly over the tater tots in the pie dish.
Bake for 30 minutes or until the center of the quiche is set. Remove from the oven and allow to cool for at least 5 minutes before slicing and serving. Top with freshly chopped parsley, if desired. Enjoy!