Cook the spaghetti in salted water as usual. In the meantime, peel off the shallot and the clove of garlic and dice finely. Finely grate the Parmesan, Gruyere and Emmental cheese, cut the Gorgonzola into small cubes and set aside.
Melt the butter in a large, deep, coated pan and sweat the shallot and garlic cubes in it until translucent. Then dust with the flour, stir everything well, gradually stir in the milk, always stirring.
Let the sauce simmer gently for about 5 - 8 minutes over low heat, stirring occasionally. Now stir the cheeses into the sauce over a very low heat. Stir until all the cheeses are well mixed with the sauce.
Season with salt, pepper and a few squirts of lemon juice and mix immediately with the hot, freshly cooked pasta and serve. Sprinkle with parsley to taste.
Tip: It also tastes very good to add a red pepper cut into small cubes.