Preheat oven to 375°F (190°C).
Cook penne pasta in a large pot of salted boiling water according to package instructions until al dente. Drain and set aside.
In a large skillet, heat olive oil over medium-high heat. Add chicken pieces and cook until browned and cooked through, about 6-8 minutes. Remove chicken from skillet and set aside.
In the same skillet, add diced onion and cook for 2-3 minutes until softened.
Add minced garlic, diced red bell pepper, diced zucchini, and sliced mushrooms to the skillet. Cook for 5-6 minutes until vegetables are tender.
Reduce heat to medium-low. Add butter to the skillet and let it melt.
Pour in heavy cream and whole milk. Stir to combine and bring to a gentle simmer.
Add grated Parmesan cheese and Italian seasoning. Stir continuously until the sauce thickens slightly, about 3-4 minutes.
Season the Alfredo sauce with salt and black pepper to taste.
Return cooked chicken to the skillet and stir to coat with the sauce.
Add cooked penne pasta to the skillet and toss everything together until well combined.
Transfer the mixture to a 9×13 inch freezer-safe baking dish. Let it cool completely.
Cover the dish tightly with aluminum foil and label with date and instructions.
To freeze: Place the covered dish in the freezer for up to 3 months.
To bake from frozen: Preheat oven to 375°F (190°C). Remove foil and cover with fresh foil. Bake for 45-50 minutes until heated through and bubbly. Remove foil during the last 10 minutes to brown the top if desired.