Cook broccoli in boiling salted water until barely tender. Combine in saucepan: tuna, soup or sauce, milk and half cup of grated cheese. Heat until almost boiling. Place layer of cooked broccoli in shallow greased casserole. Cove with layer of tuna mixture. Repeat. Sprinkle with one third cup grated cheese. Bake at 180ºC . for 20-25 minutes.