Cut the onion into 1cm slices and remove the core. Trim the celery and slice diagonally into 1cm pieces.

Bring the beef to room temperature and season with salt and pepper.

Heat salad oil in a pan over medium heat and sear the beef on all sides until browned.

Place the onion, celery, and seared beef on a baking tray lined with parchment paper. Roast in a preheated oven at 200°C for 20 minutes. Wrap the beef in aluminum foil and let it cool. Reserve the juices from the tray.

For the gravy sauce, heat the reserved vegetables and red wine in a pan over medium heat. Once boiling, add the meat juices and water, then simmer until reduced by half.

Add butter, salt, and black pepper to the sauce. Mix well, then strain through a sieve.