01 - Heat the vegetable oil in a large frying pan over medium heat. Add the finely chopped onion and cook for 3 to 4 minutes until softened.
02 - Add the minced garlic, diced carrots, and celery stalk to the pan. Stir occasionally and cook for 4 to 5 minutes until softened.
03 - Increase heat to medium-high and add the minced beef to the pan. Brown the meat for 5 to 6 minutes, breaking up any lumps with a wooden spoon.
04 - Stir in the tomato paste and cook for 1 minute to intensify the flavor.
05 - Pour in the canned chopped tomatoes and beef stock. Add Worcestershire sauce, dried thyme, bay leaf, salt, and freshly ground black pepper. Stir thoroughly.
06 - Bring the mixture to a boil, then reduce the heat to maintain a gentle simmer. Cook uncovered for 20 minutes, stirring occasionally, until the sauce thickens and vegetables are tender.
07 - Remove the bay leaf, taste, and adjust seasoning if necessary. Serve warm.