Begin by bringing a large pot of salted water to a boil. Add the spaghetti and cook according to package instructions, roughly 8-10 minutes, until al dente. Drain and set aside.

In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add the chopped onion and bell pepper, cooking for about 5-7 minutes until they soften.

Stir in one can of cream of chicken soup, 1 cup of sour cream, 1/2 teaspoon garlic powder, and 1/2 teaspoon onion powder. Add 1/2 cup of milk or chicken broth and mix until smooth.

Fold in 2 cups of shredded cooked chicken and half of the shredded Monterey Jack cheese into the mixture. Cook for another 2-3 minutes.

Gently add the drained spaghetti to the creamy chicken mixture, tossing to coat. This should take about 1-2 minutes.

For a baked finish, preheat your oven to 350°F (175°C). Transfer to a greased baking dish and sprinkle the remaining cheese on top. Bake for 20-25 minutes.

Serve warm, garnished with chopped fresh parsley if desired.