Set up your barbecue for direct cooking. Place a casserole dish (without lid) at the centre of the grill and add 2 tablespoons oil. Preheat on high for 10 minutes.
Lightly oil the steak and season with salt and pepper.
Once your barbecue is preheated, leave the heat setting on high. Add the onion, garlic, prosciutto, and mushrooms to the casserole dish and cook for 5 to 6 minutes, stirring occasionally. At the same time, add the beef to the grill around the casserole dish. Cook for 3 to 4 minutes per side, 6 to 8 minutes in total. When the onion mixture is cooked, add the flour and stir through, then add the beef from the grill.
Related Grill Skills
Chopping an Onion
Remove the casserole dish from your barbecue wearing heatproof/oven gloves.
Turn your barbecue to the roast setting (add a convection tray and trivet if using a Q) using tongs and/or heatproof gloves.
Add the stock and wine to the casserole, stir through, then add the thyme and bay leaves. Place the lid on the casserole dish and place on the barbecue. Cook for 2 hours.
In a bowl rub the butter into the self-raising flour. Stir in the Parmesan and milk. Combine well. Roll into 25 to 30 small balls and place on top of the casserole. Leave the lid off the casserole dish and cook until the dumplings are golden and cooked through, 20 to 25 minutes.