Mix beef, garlic, parsley, half the olive oil, salt, and pepper by hand.
Shape the mixture into 40 small meatballs.
Fill a pan halfway with water and bring it to a boil on the hob.
Place a large plate over the pan and add the remaining olive oil and water to the plate.
Reduce the heat to medium so the water simmers gently.
Arrange meatballs on the plate and cover with an upturned glass bowl.
Steam for 30 minutes, turning the meatballs over halfway through the cooking time.
Remove cooked meatballs and pour the remaining cooking liquor into a separate pan.
Add the cooked pasta, tomatoes, and parsley to the liquor and toss well.
Serve the pasta combined with the steamed meatballs.