Combine ground beef, bread crumbs, milk, and onion soup mix together in a large bowl until well combined; shape into 8 patties.
Heat oil in a large skillet over medium-high heat. Dredge patties in flour just to coat, and quickly brown on both sides in the hot skillet.
Place browned patties into the slow cooker stacking alternately like a pyramid.
Mix condensed soup, water, and au jus mix together in a medium bowl; pour over the beef patties.
Cook on Low until ground beef is well done, about 4 to 5 hours.
