Baked Cheesy Chicken Penne

Ingredients:
6 tablespoons butter, plus more for baking dishes(or Pam)
Kosher salt and black pepper
1 pound penne pasta
1 teaspoon olive oil
2 boneless, skinless chicken breasts, halved horizontally*  
1/2 cup plus 2 tablespoons flour
6 garlic cloves, finely minced
6 cups whole milk (I use 2% and it works great too)
8 oz mushrooms, sliced
One can stewed, diced tomatoes (I used the ones with basil and oregano)
1 tsp. oregano
1 tsp. Italian seasoning
1 1/2 tsp. garlic salt
1 1/2 cups shredded provolone (6 ounces)
1cup freshly grated Parmesan (about 6 ounces)
Optional:  Add any vegetables you like.  I put in a pkg of frozen spinach and 1 can of corn.  

1. Preheat oven to 400. Butter two shallow 2-quart baking dishes. If you’re going to freeze one, use a disposable foil pan.  In a large pot of boiling salted water, cook pasta 3 minutes short of al dente (it cooks a bit more in the oven so you don't want to get it too soft or it will be mushy); drain pasta and set aside.
2. While pasta is boiling, heat oil over medium-high heat in a large skillet. Season chicken with salt and pepper; cook through, 3 to 5 minutes per side. Halve each piece lengthwise, then thinly slice crosswise.  While chicken pan is still hot, toss the mushrooms in and saute until golden brown (3-4 minutes).  Use a little extra olive oil if needed.
3. In a 5-quart Dutch oven or heavy pot, melt butter over medium. Add flour and garlic; cook, whisking, 1 minute. While whisking constantly, gradually add milk; bring to a simmer.  Keep whisking frequently as sauce thickens, about 1 minute more. Add mushrooms and tomatoes (and any veggies you're using); cook 1 minute. Take the pan off the heat and and gradually stir in provolone and 1/2 cup Parmesan.
4. Add chicken and pasta to pot; season with oregano, Italian seasoning, garlic salt and pepper to taste. Divide pasta mixture between baking dishes. 
5. Bake, uncovered, until top is golden and bubbling, about 25 minutes. Let stand 5 minutes before serving.

Freezer instructions:
To freeze, prepare through step 4 and then let pasta cool.  Cover pan well with plastic wrap.  Place extra cheese in baggie (for topping) on top and then cover entire pan well with foil.  Freeze for up to 3 months.  To bake, preheat oven to 400.  Remove foil and plastic from pan and set cheese baggie aside.  Place foil back on pan and bake for about 1 1/2 hours.  Remove foil, stir pasta, and top with cheese.  Return pan to oven and bake for an additional 10-15 minutes or until mixture is hot and bubbly throughout.

 *For a vegetarian option you can easily leave out the chicken and add more vegetables.  That's how I did it.