Pour 2 to 3 tablespoons of the olive oil into a heavy casserole. Add a little of the onion and olives and a few slivers of anchovy. Cover with a layer of the cauliflower flowerettes, some slices of cheese, a pinch of salt, a sprinkling of olive oil, then onion and anchovies. Repeat until all the ingredients are used up, ending with a good sprinkling of olive oil over last layer of cauliflower. Pour in the wine, cover pan and cook gently until the cauliflower is tender. By this time all the liquid should have evaporated. If not, increase heat for a few minutes. Do not stir cauliflower at all. Turn out on to a round serving dish, generously garnished with croutons and serve