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

In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add 1/2 cup chopped onion, 1/2 cup chopped bell pepper, and 1/2 cup sliced mushrooms. Sauté for 5-7 minutes until soft and fragrant.

Reduce heat to low and stir in 1 can of cream of chicken soup and 1 cup sour cream with the sautéed vegetables. Add 1/2 teaspoon garlic powder, 1/2 teaspoon onion powder, and 1/2 cup milk or chicken broth. Mix well and heat for 2-3 minutes.

Stir in 2 cups shredded cooked chicken and half of the shredded Monterey Jack cheese (about 1/2 cup). Heat while stirring gently for another 2-3 minutes until cheese melts completely.

Add the drained spaghetti to the skillet and gently toss the ingredients together until the pasta is fully coated with the sauce.

For extra creaminess, preheat your oven to 350°F (175°C). Transfer the mixture to a greased baking dish and sprinkle the remaining 1/2 cup Monterey Jack cheese on top. Bake for 20-25 minutes until bubbly and golden brown.

Remove from oven, allow to sit for a few minutes, and garnish with freshly chopped parsley. Serve warm with garlic bread or a crisp salad.