Roughly dice the beef. Wash the thyme and shake dry.
Peel the onions and garlic. Cut the onion into slices and finely chop the garlic.
Turn the meat cubes in the flour and wipe off the excess. Heat the oil in a pan and fry the meat cubes in batches until browned all over. Transfer the meat to a casserole dish.
Add the onions and the garlic to the pan and fry for 10 minutes until browned, stirring occasionally.
Place the browned onions and garlic in the dish.
Grate the lemon zest. Add the zest, vegetable stock , beer, thyme and 2 tsp lemon juice to the meat. Season with salt and pepper. Cover and bring to the boil. Simmer for 2 hours over a medium heat. If necessary, add some extra beer or stock.
Add the sugar or honey shortly before the end of the cooking time. Season again with salt and pepper. Serve with pasta or polenta.