Clean, wash and drain the carrots and broccoli. Cut carrots into thick slices and broccoli into florets. Wash, peel and slice the potatoes. Bring the stock to the boil. Add potatoes and carrots to the stock and cook covered for 14-15 minutes. After 8-9 minutes add broccoli florets and cook. Put vegetables and potatoes on a sieve, drain and collect the broth.
Measure out 100 ml broth. Heat the fat in a small saucepan and sauté the flour in it. Add stock and milk while stirring, bring to the boil and simmer for about 5 minutes. Melt 20 g cheese in the hot sauce and season with salt, pepper and nutmeg. Put the vegetables and potatoes into a greased ovenproof dish and pour the sauce over them. Sprinkle with remaining cheese and sunflower seeds. Bake in a preheated oven (electric: 200 °C/ gas: level 3) for 20-25 minutes