Toss beef with flour until coated. Spray a large non-stick pan with olive oil cooking spray. Heat pan over a medium heat. Add beef to pan, cook, stirring occasionally, until browned, about 5 minutes. Place beef on a plate. Wipe the pan out with paper towels.
In the same pan, melt margarine over a medium heat. Add onion and carrot to pan and cook, stirring frequently, until the onion is soft, about 5 minutes. Add beef, wine, tomatoes and thyme.
Cover and bring to the boil. Reduce heat to medium-low. Cook for 20-25 minutes until beef and vegetables are tender.
Add pastrami, mushrooms and spring onions to the pan. Cook over a medium heat for 5 minutes. Serve.