Clean and wash the cauliflower and broccoli and divide into florets. Cook cauliflower in boiling salted water for about 15 minutes, add broccoli after about 5 minutes and cook. Drain the vegetables and collect the cooking water.
Place the vegetables in a greased ovenproof casserole dish. Heat the fat and sauté the flour in it. Deglaze with milk and 1/4 litre cooking water. Bring to the boil while stirring and simmer at low heat for about 10 minutes.
Meanwhile, dice the ham and sprinkle over the vegetables. Grate cheese and stir half of it into the sauce. Season the sauce to taste with salt, pepper and curry. Pour over the vegetables. Sprinkle the rest of the cheese and sunflower seeds on top.
Bake in a preheated oven (electric range: 200 °C/ gas: level 3) for about 15 minutes until golden brown.