Bring a 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 pot to steam them briefly, then drain everything together.
Season the chicken breast with sea salt, black pepper, and dried oregano.
Heat the olive oil in a large skillet over medium-high heat and sear the chicken for 5-7 minutes per side until cooked through and golden.
Remove the chicken from the pan, let it rest for a few minutes, then slice into strips.
In the same skillet, lower the heat to medium and sauté the minced garlic for 1 minute until fragrant.
Whisk together the Greek yogurt, chicken broth, and Parmesan cheese in a small bowl, then pour into the skillet with the garlic.
Stir the sauce constantly for 1-2 minutes until warmed through and slightly thickened, being careful not to let it boil.
Add the cooked pasta, broccoli, and sliced chicken back into the skillet, tossing well to coat everything in the sauce.
Garnish with fresh chopped parsley and serve immediately.