Clean, wash and cut the broccoli into florets. Cook in boiling salted water for 6-8 minutes. Drain in a sieve. Meanwhile prepare noodles in boiling salted water according to package instructions.
Pour into a sieve, quench and drain well. Wash and halve the tomatoes. Peel and finely chop the onion. For the sauce, melt the fat in a pot, sauté the diced onion in it, dust with flour, sauté and gradually add stock and milk.
Boil up while stirring. Stir in 75 g cheese, season to taste with salt, pepper, sugar and nutmeg. Mix pasta, broccoli, tomatoes and sauce. Pour into an ovenproof dish, sprinkle with 25 g cheese. Bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 30 minutes.