Set a large pan over medium heat, add oil and quarter of butter.

Add the beef and brown all sides, set aside in a large pot.

In the same pan, add another quarter of the butter and then add potatoes, carrots, onions and leek. Cook until browned and softened. Set aside.

In the same pan, heat the remaining butter, add flour and stir until light brown. remove from heat and gradually add the stock and red wine. Return to heat and stir until sauce thickens

Add sauce to the pot containing the meat, add tomato paste and Worcestershire sauce and simmer, covered for about 2 hours or until the beef is nice and tender. (Ensure the beef is turned occasionally)

Add the Vegetables and cook for a further 15 minutes.