• Preheat the oven to 400°F. Lightly grease a 9x9-inch baking pan. In the pan, combine pasta, flour, ¼ teaspoon salt, ¼ teaspoon pepper, red pepper flakes, broth, milk, and sun-dried tomatoes. Gently stir until no flour clumps remain. Scatter mushrooms and chicken breast over mixture and season with remaining salt and pepper. Cover with foil. Bake for 25 minutes.
• Gently stir mixture and return to oven, uncovered, for 10-15 minutes. Mixture will thicken as it cools.

To eat immediately:

• Stir in kale (or spinach) and shredded cheese, and return to oven for 5 more minutes, until cheese is bubbly.

To prepare and freeze:

• Cook as directed, then stir in the kale and cheese and allow mixture to cool completely before covering tightly with foil. Freeze up to 2-3 months.

To reheat from frozen:

• Preheat oven to 350°F. Cook, covered with foil, for 30 minutes. Add ½ cup broth or water and stir. Cover and bake 10 minutes longer or until warm throughout. Uncover, stir again, and cook for 5 more minutes (you can top with additional cheese at this point).