Sort the spinach, wash and drain well. Peel and finely chop the onions. Peel garlic and chop finely. Heat the oil in a very large pot. Brown the onions and garlic in it. Add the spinach, steam it and let it collapse for a short time.
Season with salt, pepper and nutmeg. Pour into a sieve and drain well.
Grate the cheese for the béchamel. Melt butter in a pot. Dust with flour and sauté lightly while stirring. Add 400 ml water and cream while stirring constantly and bring to the boil. Add the stock and simmer for about 5 minutes while stirring.
Stir in half the cheese. Season with salt, pepper and 1 pinch of sugar.
Take the pasta dough out of the package and unroll it with the paper. Depending on the manufacturer, either use the entire pasta dough or cut it in half together with the paper (see tip on the right). Season crème fraîche with salt and pepper.
Spread the pasta dough on the other half. First spread spinach, then salmon evenly on top. Roll up the noodle plate (see tip below).
Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Pour some sauce into a large flat casserole dish. Carefully place the pasta roll inside. Pour the rest of the sauce evenly over the pasta.
Wash the cherry tomatoes, cut them in half and spread them on top. Sprinkle with the rest of the cheese. Bake in a hot oven for 30-40 minutes.
Wash the dill, shake dry and cut finely. Take the pasta roll out of the oven. Serve sprinkled with dill.