Cook the whole wheat penne according to package instructions until al dente, adding the broccoli florets to the boiling water during the last 3 minutes of cooking.
Drain the pasta and broccoli, reserving 2 tablespoons of the starchy pasta water.
Season the chicken breast with sea salt, black pepper, and onion powder.
Heat the 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, lower the heat to medium and add the minced garlic, sautéing for 30 seconds until fragrant.
Whisk together the Greek yogurt, grated parmesan, and the reserved pasta water in a small bowl to create a smooth sauce.
Add the cooked pasta, broccoli, and chicken back into the skillet and pour the yogurt mixture over the top.
Toss everything together gently over low heat for 1 minute until the sauce is creamy and coats the pasta evenly.
Garnish with freshly chopped parsley and serve immediately.