Bring a large pot of salted water to a boil and cook the whole wheat penne according to package directions.
During the last 3 minutes of pasta cooking, add the broccoli florets to the same pot to steam until tender-crisp.
Reserve 2 tablespoons of the starchy pasta water, then drain the pasta and broccoli.
Season the chicken breast with sea salt and black pepper on both sides.
Heat olive oil in a medium skillet over medium heat and cook the chicken until golden and cooked through, approximately 5-6 minutes per side.
Remove the chicken from the skillet, let it rest for a few minutes, then slice into thin strips.
In the same skillet, reduce heat to low and add minced garlic, sautéing for 30 seconds until fragrant.
Whisk in the Greek yogurt, parmesan cheese, and reserved pasta water until a smooth, creamy sauce forms without boiling.
Add the cooked pasta, broccoli, and chicken strips back into the skillet and toss gently to coat everything in the sauce.
Garnish with freshly chopped parsley and serve immediately.