"The cutest meatballs we've ever seen...."
ground beef
uncooked long grain white rice
whole milk
yellow onion, finely chopped
finely chopped parsley, plus more for garnish
Worcestershire sauce, divided
garlic powder
Pinch cayenne pepper
Kosher salt
extra-virgin olive oil
(28-oz.) can whole peeled tomatoes, pureed
Freshly ground black pepper