Heat oil in a large skillet over medium heat.
Cook onion and celery until tender but not browned; about 5 minutes.
Mix ground beef, breadcrumbs eggs, cooked celery and onion and brown gravy mix in a large bowl. Divide into 6 equal portions and form into patties.
Heat the same pan you used for the celery and onions over medium high heat. Brown patties on both sides. Remove from the pan.
In the same pan, cook the onions for 5 minutes, being careful not to burn the onions. Deglaze the pan with the wine then add the beef stock, salt and pepper.
Return the patties to the pan with the onions and stock, bring to a boil, cover then reduce heat to low. Cook for 20 minutes.
To make gravy, remove the beef patties from the pan, mix the flour and water and whisk into the pan liquid. Cook, whisking frequently, until it bubbles. Cook over low heat for 3-5 minutes. Return patties to the pan and heat through.