Preheat oven to 350 degrees.

• Fill a 12 inch skillet with water and couple tablespoons of salt. Bring to a boil. Place pasta shells in boiling water and let cook for 5 minutes. Drain water from shells and set aside. (Pasta should be slightly under done.)
• Place cooled chicken breasts in a bowl of stand mixer, give it a few pulses to get chicken shredded. You can also shred with forks or in a food processor.
• Spoon marinara sauce into the bottom of baking dish, just enough to barely cover the bottom of the pan.
• Add ricotta, Italian spice blend, 1 cup Italian cheese blend or shredded mozzarella, and milk to shredded chicken and give a few more pulses until ingredients are incorporated. Fold in chopped spinach, once you have spinach incorporated into the filling, place chicken ricotta filling in a zip-loc bag, and snip one of the corners, pipe filling into each shell. Or you can also spoon mixture into each shell.
• When all shells are filled spoon the remaining marinara sauce over the shells, and sprinkle with remaining shredded cheese. Cover with aluminum foil and bake at 350 degrees for 30 minutes remove foil and bake for an additional 10 minutes.
• Make ahead meal: This meal can be made up to two days in advance, cover with aluminum foil and store in refrigerator until ready to bake.
• Freezer directions: If you are making this meal to freeze you will want to put in a freezer safe baking dish/ pan cover tightly with plastic wrap and foil. Remove from freezer, thaw, remove plastic wrap and cover with aluminum foil and place in a preheated 350 degree oven cook for 30 minutes with foil on, remove foil and cook for another 10 minutes.