Bring a large pot of salted water to a boil and cook the tagliatelle according to package directions until al dente.
Reserve 0.25 cup of pasta water before draining the noodles.
Heat the olive oil in a large skillet over medium-high heat and add the diced chicken breast.
Season the chicken with half of the sea salt and black pepper, cooking for 6 minutes until golden and cooked through.
Remove the chicken from the skillet and set aside.
Add the sliced cremini mushrooms to the same skillet and sauté until they are browned and tender.
Add the minced garlic to the mushrooms and cook for 30 seconds until fragrant.
Lower the heat to low and whisk together the Greek yogurt, truffle oil, and reserved pasta water in a small bowl.
Return the chicken and cooked pasta to the skillet.
Pour the yogurt mixture over the pasta and toss gently to coat until the sauce is creamy and warm.
Garnish with parmesan cheese, fresh parsley, and the remaining salt and pepper before serving.