1. In a large mixing bowl, mix beef, onion mix, bread crumbs, and milk. Divide into 8 patties and shape into oval patties. Dredge in flour and set aside.
2. Heat olive oil over med-hi heat. Brown the patties. Transfer to a slow cooker.
3. In another bowl, whisk together mushroom soup, au jus, and water. Pour over the patties.