Finely chop the onion and garlic, and cut the champignons into thin slices.

Boil water in a pan, then add onions, garlic and mushrooms. Add salt and chopped spinach.

Cover the pan with a lid and cook at a medium temperature for 10 to 15 minutes (or until the vegetables soften).

Meanwhile, prepare the cream by mixing all the ingredients for the dressing in a blender. Add it in a pan to the rest of the ingredients and combine well.

Put some filling in a baking dish, fill the pasta with the filling, place it in the baking dish and cover all of it with the dressing.