If using oven, pre-heat to 180°C, else turn on slow cooker to high
Use a heavy bottomed pan to sauté the onion and leek stem in olive oil until softened.
Add garlic and mushrooms and sauté for 2-3 minutes
Add carrots, celery and the leek leaves and continue cooking for 3-4 minutes
Cut the meat into 4cm pieces and sprinkle with seasoned flour.
Add meat to the mixture and mix well, then add 1-2 cans of tomatoes, the wine, and herbs and bring to the boil
Transfer to the slow cooker or casserole dish if using them, or cover pan with aluminium foil, and place in oven
Cook for 4-5 hours until the meat easily breaks up.
Season to taste. Remove rosemary sticks and bay leaves.