Chicken & Spinach Pasta Bake

I have made this twice now for my family.  The first time I followed the directions almost exactly.  The second time I modified it a little, and I thought it was even better.  My girls in particular gobbled this up.  :-)

Ingredients
13-15oz box multigrain penne pasta (or whatever pasta you want really)
1 T olive oil
1 small onion or 1/2 a large, diced
10oz fresh spinach
1 lb chicken breasts, cooked and shredded (omit for vegetarian)
1 can Italian style diced tomatoes
8oz container chive and onion cream cheese
1/2 tsp salt
1/2 tsp pepper
1 1/2 cups shredded mozzarella cheese

Directions
Cook pasta according to directions.  Put your spinach in the food processor and pulse until no more big pieces are left.  I also did this to my tomatoes since they were large pieces.  In a small skillet, sautee your onion in the oil until soft.  In a large bowl, combine pasta, onion, spinach, chicken, tomatoes, cream cheese, and salt and pepper.  Spoon into a sprayed 9x13 casserole dish.  Sprinkle top with mozzarella.  Bake covered at 375 degrees for 30 minutes and then uncover and bake an additional 15 minutes.

This is a great prepare ahead of time meal you can put in the fridge and pop in the oven before serving.  Add 10-15 minutes on to the covered bake time if you bake it directly out of the fridge.