Bring a pot of salted water to a boil and cook the fettuccine until al dente according to package directions.
Reserve 0.25 cup of the starchy pasta water, then drain the noodles and set aside.
Season the chicken breast evenly with sea salt, black pepper, and garlic powder.
Heat the olive oil in a skillet over medium-high heat and sear the chicken until golden brown and cooked through.
Remove the chicken from the pan, let it rest for 2 minutes, and then slice into thin strips.
In the same skillet, reduce the heat to low and sauté the minced garlic for 30 seconds until fragrant.
Whisk together the Greek yogurt, parmesan cheese, and the reserved pasta water in the skillet to create a smooth sauce.
Add the cooked fettuccine and chicken strips back into the skillet, tossing gently to coat everything in the sauce.
Garnish with freshly chopped parsley and serve immediately.