Cook the pasta in plenty of boiling salted water for about 10 minutes. Drain the noodles.
Wash and slice the tomatoes. Clean and wash spring onions and cut them into rings.
Heat the fat. Sauté spring onions in it, dust with flour and sauté briefly. 1⁄4 l Stir in water, milk and stock, bring to the boil. Simmer for about 3 minutes. Grate the Gouda and melt in the sauce while stirring.
Season to taste with salt, pepper and nutmeg.
Spread the pasta in a large greased casserole dish. Pour the sauce over it. Place tomato slices on top. Season with salt and pepper. Grate the parmesan and mix with the breadcrumbs. Sprinkle over the tomatoes.
Bake in the preheated oven (electric oven: 200 °C/circulating air: 175 °C/gas: level 3) for 20-30 minutes until the surface is golden brown.