To a 9X13 baking dish, add dry uncooked pasta, marinara sauce, chicken stock, water, milk, olive oil, Italian seasoning, red pepper flakes, and salt. Stir everything.
Arrange cooked meatballs on top. Cover tightly with foil and bake for 35-40 minutes.
Carefully take out the baking dish from the oven( it's gonna be heavy).
Remove foil. Gently stir once and check the doneness of the pasta. (Keep in we are gonna bake it for another 10 minutes )
Sprinkle parmesan cheese and mozzarella over the top. Bake for another 8-10 minutes until the cheese melts and is bubbly. Broil for a few minutes to get brown spots.