Follow these simple steps to create delicious Monterey Chicken Spaghetti:

1. Boil Spaghetti: Cook the spaghetti according to package instructions in salted water. Drain and set aside.
2. Sauté Vegetables: In a large skillet, heat olive oil over medium heat. Add diced onions and bell peppers, sautéing until they are soft and translucent.
3. Combine Chicken and Sauces: In the skillet, add shredded chicken, marinara sauce, and Alfredo sauce. Stir well to combine and heat through.
4. Season the Mixture: Add garlic powder, Italian seasoning, salt, and pepper to taste. Stir to ensure the chicken and sauce are well-seasoned.
5. Mix with Pasta: Add the cooked spaghetti to the skillet. Toss everything together until the pasta is well coated with the sauces.
6. Transfer to Baking Dish: Preheat your oven to 350°F (175°C). Transfer the spaghetti mixture to a greased baking dish.
7. Add Cheese: Sprinkle the shredded Monterey Jack cheese evenly over the top of the pasta.
8. Bake: Place the baking dish in the preheated oven and bake for 20 minutes or until the cheese is melted and bubbly.
9. Garnish: Remove from the oven and let it cool for a few minutes. Garnish with freshly chopped parsley, if desired.

These steps will ensure your Monterey Chicken Spaghetti is loaded with flavors and ready to wow your family and friends.