Cut crusts off bread then tear bread into pieces. In a bowl, combine milk and olive oil, stir in the bread then set aside until absorbed. Whisk with a fork.
Mix together beef mince, pork mince, garlic, onion, salt, zest, juice, cheese, parsley and pepper. Shape into balls then refrigerate for 30 minutes.
Heat oil in a saucepan. Stir in onion and saute for a minute. Add garlic and stir for 30 seconds. Stir in passata, water, salt, pepper, parsley and chillies. Lower heat and simmer at medium low for 20 minutes. Place meatballs into the simmering sauce then cook until done, about 12 minutes.
Cook pasta according to packet directions then drain. Serve pasta topped with meatballs and sauce.