Baked Penne with Chicken and Sun-dried Tomatoes

I read recipe books and magazines like they are good novels. This recipe came in the recent Everyday Food, and I knew as soon as I saw the title, that this was a book worth judging by the cover. The notes suggest making double and freezing half. I usually don't do that until I have tried and loved a recipe, but can assure you next time I make this, I'll be doing double.
*3 TBSP. butter, plus more for baking dish
*coarse salt and ground pepper
*1/2 lb. penne rigate (I use the cute mini penne noodles)
*1 tsp. olive oil
*1 chicken breast, 8 oz. (I used 4 large tenders)
*1/4 c. + 1 TBSP. flour
*2 garlic cloves, minced
*3 cups whole milk (love having a 1-yr-old to keep such goodness in the fridge)
*5 oz. white mushrooms, trimmed and thinly sliced (I used the canned I had on hand)
*1/4 c. oil-packed sun-dried tomatoes, drained and thinly sliced (I use regular dried, no oil)
*3/4 c. shredded provolone (3 oz.) - (I only had about 1/2 c. so I used mozzarella for the rest)
*1/2 c. finely grated Parmesan, plus more for topping

Preheat oven to 400. Butter a shallow 2-quart baking dish. Ina large pot of boiling salted water, cook pasta 3 minutes short of al dente; drain pasta, and return to pot.
In a nonstick skillet (I used a big one to save a dish in a minute), heat oil over medium-high. Season chicken with salt and pepper; cook until opaque throughout, 3-5 minutes per side. Thinly slice crosswise. (Put chicken on top of drained pasta while working on sauce).
In a large Dutch oven or heavy pot (I used the skillet from the chicken, just wiped out what was left of the oil), melt butter over medium. Add flour and garlic' cook, whisking, 1 minute. While whisking, gradually add milk; bring to a simmer, whisking frequently. Add mushrooms and tomatoes; cook 1 minute. Remove from heat and stir in provolone and Parmesan.
Pour sauce over the pasta and chicken. Stir well and pour into baking dish. Sprinkle with 1/4 c. Parmesan.
Bake, uncovered, until top is golden and bubbling, about 25 minutes (mine had been in the fridge all day and took about 35 min). Let stand 5 minutes before serving.
This made 4 very large portions and this picture does not do it justice. The hubby and I sat nibbling at the crunchy top noodles long after we were done.
Note: To freeze - Prepare pasta as directed, but instead of baking, let cool. Cover tightly with foil and freeze for up to 3 months. To bake from frozen, bake (still covered with foil) on a rimmed baking sheet until center is hot, about 1.5 hours. Remove foil and bake until golden, about 15 minutes more.