How to make it
Heat 1 tbsp oil then pan fry the steak for 2-3 minutes on each side. Add butter and mix well. Arrange the steak on plate and keep warm.
Use the same skillet with the remaining oil to sauté onion and mushrooms. Add flour and toss well. Slowly pour in seasoning mix and cook until sauce thickened.
Pour red wine sauce over the steak to serve with potatoes and vegetables.