Healthy Squash and Chicken Casserole

I'm trying to catch up on some of the recipes that I've tried over the last week and really enjoyed.  Most of them are adapted from Clean Eating Quick and Easy Meals, which came from Oxygen Magazine.  The following was a hit last week for dinner!

Healthy Squash and Chicken Casserole (serves 8)
Ingredients:

• 10 slices of whole wheat bread (i used 1/2 bag stuffing mix b/c we didn't have bread and added 1/2 cup water to it)
• 1 yellow onion, thinly sliced
• 3 medium yellow squash, thinly sliced
• 2 cloves of garlic, minced (i used 1 tbsp of roasted garlic)
• 1/2 lb chicken breast (i used 10 boneless, skinless chicken breast tenders)
• 1 cup shredded low-fat mozzarella cheese
• 2 tsp Italian seasoning (didn't use b/c of the stuffing)
• sea salt and pepper

Directions:

• Cut bread into cubes and let air dry overnight on cookie sheet OR toast it in oven for 10 minutes at 350 degrees.  (didn't need to do this)
• Preheat oven to 350 degrees
• Heat a large nonstick skillet on high for one minute.  Reduce heat to medium-low, mist with cooking spray and add onion.  Saute for 8 minutes or until caramelized.   Add squash and garlic. Mist with more cooking spray if needed, and saute until cooked, about 5 minutes.  
• Remove vegetables from pan and mist with spray again.  Add chicken and cook until golden brown on each side, about two to three minutes total. 
• In a large bowl, mix together cooked vegetables and chicken and bread cubes.  Mix in mozzarella, seasoning, and salt and pepper.  
• Pour mixture into a 8 cup casserole dish and bake for 15 minutes, until cheese is melted and casserole is lightly browned on top.