Pop the beef into a bowl and toss it with the flour salt and pepper.
Heat a tablespoon of olive oil in a large heavy-based pot over high heat and pour the floured beef into the pot. Cook it until it is browned on all sides. About 5 - 8 minutes. There will be pieces that stick to the bottom, but don’t worry about that.
Remove the beef from the pot and set aside. Then pour in the remaining olive oil and the prepared onions, garlic, carrots, celery, mushrooms, and potatoes. Saute for 5 minutes.
Toss the beef back into the pot along with the Guinness, crushed tomato, beef stock, bay leaves, tomato paste, Italian herbs and a pinch of salt and pepper. Cover with the lid and bring to a boil, then turn down the heat and simmer for 45 minutes.
Add the zucchini and simmer for another 15 minutes.
Serve with parsley chopped on top.