Place onion and smashed garlic in slow cooker.

Season chicken with salt and pepper and place on top of onions. Pour sauce over chicken. Sprinkle dried basil on to the sauce. Cook on low for 5-6 hours.

When slow cooker time is up, remove chicken, shred and place back into sauce. Stir in Parmesan cheese.

Prepare pasta according to package instructions. Drain pasta and stir into slow cooker.

Sprinkle Mozzarella cheese over the top of pasta and replace cover just until cheese melts, about 10 minutes.

Garnish with parsley just before serving.