Place the beef on a plate and sprinkle over the cornflour. Season with salt and black pepper and toss to coat the beef all over.
Spray a large frying pan with low calorie cooking spray and place over a medium high heat. When the frying pan is hot, add the beef and fry for about 3-4 minutes, turning to seal and brown on all sides. Place the beef in the slow cooker pot.
Lower the heat to medium and spray the frying pan again with low calorie cooking spray. Add the bacon, scraping up any meaty bits from the bottom of the frying pan and stir in. Fry the bacon for 4-5 minutes until cooked and lightly browned around the edges. Add the bacon to the beef in the slow cooker pot.
Spray the frying pan again if needed and place on a medium heat. Add the onion and fry for 5 minutes until it softens and turns golden, again scraping up any meaty bits in the frying pan and stirring in. Add the garlic and cook for a further 1-2 minutes.
Add the carrots and mushrooms and cook for 4-5 minutes to lightly brown. Add the vegetables to the slow cooker pot.
In a measuring jug, mix the hot stock, red wine stock pots, tomato puree, balsamic vinegar, Worcestershire sauce, parsley, thyme and bay leaves. Stir until the stock pots have dissolved. Pour into the slow cooker pot and stir into the beef and vegetables.
Cover with the lid and turn the slow cooker onto the high setting. Cook for 4-5 hours. The stew will be ready when the beef is tender, and the gravy has thickened. Season to taste if needed.
Remove the bay leaves and serve with steamed vegetables or other accompaniment of your choice.