Bring a large pot of salted water to a boil and cook the whole grain penne according to package directions until al dente.
While the pasta cooks, reserve 0.25 cup of the starchy pasta water, then drain the noodles and set aside.
Season the chicken breast with sea salt and black pepper on both sides.
Heat olive oil in a large skillet over medium-high heat and sear the chicken for 5-6 minutes per side until golden and cooked through.
Remove the chicken from the pan, let it rest for 2 minutes, then slice into thin strips.
In the same skillet, reduce 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 a small bowl until smooth.
Add the cooked pasta and sliced chicken back to the skillet, then pour the yogurt mixture over the top.
Toss everything together over low heat for 1 minute until the sauce coats the pasta evenly; do not boil the sauce.
Garnish with fresh chopped parsley and serve immediately.