Place the beef and flour in a large snap lock bag. Season and toss to coat. Heat half the oil in a large casserole dish over medium-high heat. Add beef and cook, in batches, for 3-4 minutes or until lightly browned, respraying the pan with oil, as necessary. Set cooked beef aside on a large plate.
Reheat the same pan over medium-high heat with remaining oil. Add onions, celery and carrots. Cook for 3-4 minutes then return beef to pan with vinegar, tomato paste, sugar and stock. Stir well, bring to the boil, reduce heat to low and cover. Simmer gently for 1 ¼ -1 ½ hours, adding mushrooms for final 30 minutes of cooking time and removing lid. Remove from heat, season and stir through spinach.
Serve beef braise with cauliflower rice, steamed beans and parsley leaves.
Gravy beef would also work well in this recipe.
Ask your butcher to dice your beef for you to save time.
This is a great meal to have in the freezer for winter nights when you are time poor. Simply reheat the braise and serve with your choice of mash, rice, pasta or cous cous or steamed green vegetables.