Bring a large pot of salted water to a boil and cook whole wheat pasta until al dente. Reserve 1/2 cup pasta water and drain. Season chicken with salt and black pepper. Heat 1 tablespoon olive oil in a large skillet over medium heat and cook chicken for 5–6 minutes per side until golden and internal temperature reaches 165°F. Remove and let rest before slicing. In the same skillet, add remaining olive oil and minced garlic and cook for 30 seconds. Pour in chicken broth and simmer for 2–3 minutes. Stir in low-fat milk and Italian seasoning and simmer gently for 3–4 minutes. Reduce heat to low and gradually add Parmesan cheese while stirring until smooth. Add reserved pasta water if needed to adjust consistency. Return cooked pasta and sliced chicken to the skillet and toss until coated. Stir in spinach during the final minute until wilted. Garnish with fresh parsley and serve warm.