Cut the chicken breast into thicker strips and approximately equal-sized cubes. Put the meat in a bowl and season it with two teaspoons of sea salt, the ground pepper and the marjoram.
Cut the peeled mushrooms in half and then slice them not too thin. Chop the onion and garlic as little as possible, grate the Parmesan cheese and finely chop the parsley.
Heat two tablespoons of olive oil in a Dutch oven, then put the diced and seasoned chicken to fry.
Let them cook for about five minutes until the liquid evaporates completely, and the pieces of meat start to turn golden. Remove them to a plate.
In the same pan, without cleaning it, melt the butter and put the onion and minced garlic to sauté over medium heat for about a minute.
Add the sliced mushrooms, season with half a teaspoon of sea salt and sauté it for about five minutes.
Add the milk, double cream, and half of the grated Parmesan cheese, letting them simmer for a minute over medium heat.
When it starts boiling over low heat, add the tagliatelle pasta, and leave two minutes to cook.
Add the previously fried meat to the pan, mix lightly and let it simmer for another two minutes.
Add the other half of the grated Parmesan cheese, the chopped parsley and another teaspoon of sea salt.
Stir lightly, not to break the pasta; taste if it needs to be more seasoned and serve it as soon as it is still hot, adding more grated Parmesan cheese on top.
Notes
Instead of fresh tagliatelle, you can use penne pasta or fettuccine.If you don't want to add chicken breast, you can also use boneless chicken thigs or turkey breast, cut into cubes or strips.Be careful because fresh pasta will absorb almost all of the liquid, so if the dish is too dry, add a little more milk.