Bring a pot of salted water to a boil and cook the whole wheat penne according to package directions until al dente.
Reserve 0.25 cup of the pasta cooking water before draining the noodles.
Season the chicken breast with sea salt, black pepper, and Italian seasoning on both sides.
Heat olive oil in a large skillet over medium-high heat and sear the chicken for 5-7 minutes per side until fully cooked.
Remove the chicken from the pan, let it rest for 3 minutes, then slice into thin strips.
In the same skillet, reduce heat to low and sauté the minced garlic for 1 minute until fragrant.
Whisk together the Greek yogurt, parmesan cheese, and reserved pasta water in the skillet to create a smooth sauce.
Fold in the cooked pasta and baby spinach, stirring until the spinach is wilted and the pasta is evenly coated.
Top the pasta with the sliced chicken and serve immediately.