Cut the onions into small cubes, brush the mushrooms clean and cut into slices. Also cut the garlic cloves into small slices and finely chop the parsley. Then fry the onions in half the oil, add the spinach leaves and the garlic. After approx. 5 minutes, fill up with the broth.
Dice the Gorgonzola, add half of the parsley and the wine to the saucepan and leave on the plate over low heat.
Just before serving, add the shrimps and sour cream to the sauce base and heat gently for another 5 minutes, under no circumstances boil, otherwise the sour cream will flocculate. Season to taste with salt, pepper and nutmeg.
Heat the water in a second saucepan with salt until it boils and cook the tagliatelle al dente according to the instructions on the package.
Drain the pasta, arrange on the plates, pour the sauce over them and sprinkle with freshly grated parmesan. Garnish with the remaining parsley and serve immediately.
Tip: If you like, you can also fry cubes of salmon and serve on top of the spaghetti.