Roasted Chicken Baked Pasta

Preheat oven to 425°F with rack in middle position.

Season chicken breast halves all over with 1/2 teaspoon salt and 1/4 teaspoon pepper. Place on a 4-sided baking sheet and roast in oven until cooked through, 30 to 40 minutes. Let chicken rest until cool enough to handle, then tear into chunks, discarding bones. Reduce oven temperature to 350°F.

Melt butter in a 2-to 3-qt heavy saucepan over medium heat until foam subsides. Add flour and cook, stirring, 1 minute. Whisk in broth, water, oregano, pepper flakes and 1/2 teaspoon each of salt and pepper. Whisk until liquid comes to a boil, then let boil 10 minutes, whisking occasionally. Remove from heat and reserve.

Cook pasta until al dente in a large pot of well-salted boiling water. Drain pasta then return to pot. Add broth mixture and chicken, tossing to combine. Transfer to a 3-qt baking dish, then sprinkle evenly with cheese.

Bake until cheese is golden and liquid has been absorbed, about 45 minutes. Let stand 10 minutes before serving.