Creamy Chicken and Mushroom Spaghetti Bake

Ingredients

0 of 18 out on the counter

• 12 oz whole-wheat spaghetti
• 1½ lb boneless, skinless chicken breast, cut in 1-inch pieces
• 1 tbsp olive oil
• 8 oz white mushrooms, sliced
• 1 medium onion, diced
• ¾ tsp garlic powder
• 4 tbsp olive oil
• ⅓ cup all-purpose flour
• 2½ cups low-sodium chicken broth
• 1½ cups 1% milk
• ½ tsp dried thyme
• ¾ tsp salt
• ½ tsp black pepper
• 1 cup frozen peas
• ½ cup shredded reduced-fat cheddar cheese (2 oz), divided
• ¼ cup grated Parmesan cheese
• 1 tsp olive oil, for the dish
• 1 tbsp salt, for the pasta water

All set! Everything is out. Time to bake.

Method

1. 1Heat the oven to 350 °F and oil a 9×13 dish. Break the spaghetti in half and boil it in well-salted water 2 minutes short of the time on the box; it finishes in the oven. Water boils near 203 °F here, so taste a strand and go by the bite, not the clock. Drain and set aside.
2. 2Dry the same pot and heat the oil over medium-high. Add the chicken with ¼ tsp of the salt and cook, stirring, until no pink is left and the largest piece reads 165 °F, 6 to 8 minutes. Move it to a bowl with its juices.
3. 3Warm the 4 tbsp oil in the same pot over medium. Add the mushrooms and onion and cook until the liquid is gone and the edges are brown, about 8 minutes. Stir in the garlic powder for 30 seconds.
4. 4Sprinkle on the flour and stir for 1 minute. Pour in the broth slowly, stirring, then the 1% milk. Add the thyme, the rest of the salt (½ tsp) and the pepper. Simmer, stirring, until it coats a spoon, about 5 minutes. Stir in half the cheddar (¼ cup) until melted.
5. 5Stir in the chicken and its juices, the peas and the spaghetti. Spread in the dish. Scatter the rest of the cheddar and the Parmesan over the top.
6. 6Cover with foil and bake 20 minutes. Uncover and bake 15 minutes more, until it bubbles at the edges, is browned in spots and reads 165 °F in the center. Rest 10 minutes so the sauce settles.
7. 7Cool leftovers and refrigerate within 2 hours, in shallow containers. Reheat until it reads 165 °F: 2 minutes in the microwave, or the air fryer at 325 °F for about 10 minutes under foil.