Remove chicken from steamer; set aside. Place pasta in Multipurpose Steamer. Stir in water. Cover; microwave on high until tender, 7–8 min. Drain pasta; return to steamer. Add milk, seasoning, and butter, if using. Stir until evenly mixed.
Add chicken, tomatoes, and spinach to mac & cheese. Stir to combine.
Per serving: Calories 460, Fat 11 g (Saturated 3.5 g, Trans 0.2 g), Cholesterol 95 mg, Sodium 470 mg, Carbohydrate 50 g (Fiber 4 g, Sugars 3 g), Protein 38 g.
Go vegetarian—simply blend 1 pkg (300g) soft/silken tofu with mac & cheese.