Cook noodles according to package instructions.
Make roux sauce: Start by melting butter in a large skillet over medium heat. Once butter is melted, stir in flour until smooth then whisk in chicken broth and milk. Continue to whisk mixture until smooth.
Once roux is finished, mix in seasonings and onion. Then stir in vegetables, noodles, and turkey.
Coat 9"x13" casserole dish with olive oil or cooking spray.
Pour turkey casserole mix into casserole dish. Spread mixture evenly through dish and top with mozzarella cheese.
To freeze: Let cool completely. Seal with plastic wrap and lid and store in freezer. To bake frozen: Remove plastic wrap and loosely cover with lid or aluminum foil and bake at 375°F for 60 minutes. Remove the foil and bake for another 15 minutes or until cheese begins to bubble and is fully melted.
To bake now: Preheat oven to 375°F while prepping dish. Once dish is prepped, bake 20-30 minutes uncovered or until cheese is fully melted and begins to bubble. Add salt and pepper to taste.