Baked Penne with Chicken and Sun- Dried Tomatoes

Courtesy of Martha Stewart

Ingredients
6 tablespoon(s) butter, plus more for baking dishes
Coarse salt
Ground pepper
1 pound(s) penne rigate
1 teaspoon(s) olive oil
2 (8 ounces each) boneless, skinless chicken breast halves
1/2 cup(s) all-purpose flour, spooned and leveled
2 tablespoon(s) all-purpose flour, spooned and leveled
4 clove(s) garlic, minced
6 cup(s) whole milk
1/2 cup(s) oil-packed sun-dried tomatoes, drained and thinly sliced
1 1/2 cup(s) (6 ounces) shredded mozzarella
1 cup(s) (4 ounces) finely grated Parmesan
Optional: 10 ounce(s) white mushrooms, trimmed and thinly sliced

Directions
1. Preheat oven to 400 degrees F. Butter 9x13 dish. In a large pot of boiling salted water, cook pasta 3 minutes short of al dente; drain pasta, and return to pot.
2. In a large nonstick skillet, heat oil over medium-high. Season chicken with salt and pepper; cook until opaque throughout, 3 to 5 minutes per side. Cut into pieces.
3. In a 5-quart Dutch oven or heavy pot, melt butter over medium. Add flour and garlic; cook, whisking, 1 minute. While whisking, gradually add milk; bring to a simmer, whisking frequently. Add tomatoes; cook 1 minute. Off heat, gradually stir in mozzarella and 1/2 cup Parmesan.
4. Add chicken and pasta to pot; season with salt and pepper. Divide pasta mixture between baking dishes; sprinkle each with cup Parmesan.
5. Bake, uncovered, until top is golden and bubbling, about 25 minutes. Let stand 5 minutes before serving.
6. To make ahead, prepare through step 4; let cool. Cover tightly with foil, and freeze, up to 3 months. Preheat oven to 400 degrees F, and bake (still covered in foil) on a rimmed baking sheet until center is hot, about 1 1/2 hours. Remove foil; bake until golden, about 15 minutes more.