Warm the butter, sauté the garlic and broccoli for approx. 5 mins., season with salt. Add the water, cover and simmer for approx. 5 mins., remove. Bring the stock and milk to the boil in the same pan, stir in the polenta, simmer, stirring constantly, over a very low heat for approx. 2 mins. Return the vegetables to the pan, simmer the polenta for about another 2 mins. until a thick paste has formed. Stir in the cheese, season. Mix the flour and nutmeg. Coat the onions with the flour mix, shake off the excess. Heat the butter in a non-stick frying pan, fry the onion rings in batches over a medium heat for approx. 6 mins. until crisp, season with salt. Drain on kitchen paper. Plate up the polenta, topped with the onion rings and parsley.