1. Preheat the oven to 180-200 °C (6-7).
2. Trim the cauliflower and boil in salted water for 5-10 minutes or until just tender.
3. Melt the butter in a saucepan with nutmeg. Add the flour and stir continuously over low heat. Let the sauce cool down.
4. In a saucepan, boil the milk and pour it onto the cold flour/butter mixture. Season to taste. Mix well and cook over medium heat until the sauce thickens.
5. Drain the cauliflower florets and place them into 4 mini round casseroles. Season to taste and sprinkle with grated cheese. Pour the sauce over the cauliflower. Sprinkle with more cheese. Place in the oven for 5-10 minutes until golden brown.
6. Sprinkle with ham cubes and serve immediately, covered.