1. Preheat the oven to 150 C/Gas 2. Heat the butter and a tablespoon of the oil in a large casserole dish with a lid. Add the onions and brown them all over - this will take about 5 minutes. Sprinkle on the brown sugar and continue to cook the onions on a low heat for another 5 minutes.
2. Remove the onions, but keep the casserole dish on the heat and start to brown the meat in batches. You will probably need to add some more olive oil.
3. Once all the meat is browned, put the onions back in the dish with all the meat. Sprinkle on the flour and stir well. Pour on the beer and add enough stock to just cover the meat. Pop the bouquet garni into the pan and season with salt and pepper.
4. Bring everything to a simmer on top of the stove, then cover the casserole dish and place it in the oven for 2 hours. Serve with potatoes and savoy cabbage.