Chicken & Spinach Pasta Bake

I found this recipe on Food.com & thought it was simple enough for weeknight cooking. I was also drawn to the use of chive & onion cream cheese which did not disappoint. The original recipe used rotisserie chicken and also baked the onions in the oven first by themselves. I chose to cook some chicken breasts in the crockpot the first time I did this & boneless skinless chicken thighs the second time. I also sautéed my onions in a pan rather than the oven. Next time, I will add some fresh garlic as well & instead of putting all of the mozzarella on top, I think it would be a great idea to mix at least ½ cup into the mixture.

8 ounces uncooked rigatoni pasta
1 tablespoon olive oil
1 cup finely chopped onion (about 1 medium)
2 cloves of garlic, minced (optional)
1 (10 ounce) package frozen chopped spinach, thawed
3 cups cubed cooked chicken breasts
1 (14 1/2 ounce) can Italian-style diced tomatoes, undrained
1 (8 ounce) container chive & onion cream cheese
Salt & pepper
1 ½ cups shredded mozzarella cheese 

Prepare rigatoni according to package directions. Sauté onion & garlic in a pan with a little olive oil. Transfer to a large bowl and set aside. Drain thawed spinach well, pressing between layers of paper towels. Stir rigatoni, spinach, chicken and next 4 ingredients with onion & garlic in bowl. Add some mozz. Spoon mixture into baking dish, and sprinkle evenly with the rest of the shredded mozzarella cheese. Bake, covered, at 375 degrees for 20 minutes until all is melty. Place under broiler for a few minutes to brown the edges of pasta as well as cheese.