Bring a large pot of salted water to a boil and cook the whole wheat penne according to package directions until al dente.
While the pasta cooks, season the chicken breast evenly with the sea salt and black pepper.
Heat the extra virgin olive oil in a large skillet over medium-high heat and sear the chicken until golden and cooked through, approximately 5-6 minutes per side.
Remove the chicken from the skillet and let it rest for 2 minutes before slicing into thin strips.
In the same skillet, add the trimmed asparagus spears and minced garlic, sautéing for 3-4 minutes until the asparagus is bright green and tender-crisp.
In a small bowl, whisk together the Greek yogurt, lemon juice, and lemon zest until the mixture is completely smooth.
Drain the pasta, reserving 2 tablespoons of the cooking water to help thin the sauce if needed.
Return the cooked pasta to the skillet along with the sliced chicken, fresh baby spinach, and the yogurt mixture.
Toss everything gently over low heat for 1 minute until the spinach is just wilted and the pasta is coated in a creamy sauce.
Garnish with freshly chopped parsley and serve immediately.