Preheat your oven to 350°F (175°C) and grease a baking dish.

Cook the spaghetti according to package instructions until al dente, then drain and set aside.

Sauté in a skillet over medium heat, adding olive oil or butter. Cook the diced chicken until golden brown, around 5-7 minutes. Add the sliced mushrooms and continue cooking until tender, about 3-4 minutes.

Combine the flour with the sautéed chicken and mushrooms, then gradually stir in the chicken broth and heavy cream. Cook while stirring for about 5 minutes until the mixture thickens beautifully.

Mix in the cooked spaghetti and shredded cheddar cheese until everything is perfectly combined and the cheese is melted.

Pour the mixture into the prepared baking dish. Bake uncovered for 20-25 minutes, until it’s bubbly and golden on top.