Bring a pot of salted water to a boil and cook the fettuccine according to package directions until al dente.
Reserve 2 tablespoons of pasta water, then drain the noodles and set aside.
Season the chicken breast with sea salt, black pepper, and garlic powder.
Heat olive oil in a skillet over medium-high heat and sear the chicken until golden and cooked through, about 5-6 minutes per side.
Remove chicken from the pan, let it rest for 2 minutes, then slice into thin strips.
In the same skillet, lower the heat to low and sauté the minced garlic for 30 seconds until fragrant.
Whisk in the Greek yogurt, parmesan cheese, and reserved pasta water until a smooth, creamy sauce forms.
Add the cooked pasta and sliced chicken back to the skillet, tossing gently to coat everything in the velvety sauce.
Garnish with fresh chopped parsley before serving.