Egg and Hash Brown Casserole

Preheat oven to 425 degrees F (220 degrees C).

Toss potatoes with vegetable oil in a bowl until potatoes are well coated. Press potatoes into a 10-inch pie pan to create a crust.

Bake potatoes in the preheated oven until golden brown, about 30 minutes. Remove pan from oven and reduce heat to 350 degrees F (175 degrees C).

While potatoes are baking, heat a large skillet over medium-high heat and stir in sausage. Cook and stir until sausage is crumbly, evenly browned, and no longer pink. Drain and discard any excess grease. Combine sausage with eggs, mushrooms, pepper jack cheese, Swiss cheese, milk, 1 tablespoon parsley, garlic salt, and black pepper in a large bowl. Pour egg mixture into the prepared potato crust.

Bake in the oven until eggs are set, about 25 minutes. Arrange tomato slices over eggs and sprinkle the remaining 1 1/2 teaspoons parsley on top. Return to the oven and continue baking until tomatoes soften, about 5 minutes more.