Bring a large pot of salted water to a boil and cook the whole grain penne according to package directions until al dente.
During the last 3 minutes of pasta cooking, add the broccoli florets to the boiling water to blanch them until tender-crisp.
Reserve 0.25 cup of the starchy pasta water, then drain the pasta and broccoli.
Season the chicken breast with sea salt, black pepper, and garlic powder.
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, then slice into strips.
In the same skillet, reduce heat to low and sauté minced garlic for 30 seconds until fragrant.
Whisk together the Greek yogurt, parmesan cheese, and reserved pasta water in the skillet to create a smooth sauce.
Add the cooked pasta, broccoli, and sliced chicken back into the skillet, tossing gently to coat everything in the garlic sauce.
Garnish with fresh chopped parsley and serve immediately.