Assembly: Pour the creamy mixture over the ground beef and vegetables. Top with grated provolone and mozzarella cheese.
Bake: Bake for 25 to 30 minutes, until golden brown and bubbly.
Let rest and serve: Let the gratin rest for 5 minutes before serving. Delicious as is, or with a crunchy salad, crusty bread or toasted rolls.
We almost had a bloodbath at the table over who got the last one
