Heat a drizzle of olive oil in a large saucepan on medium heat.
Add the garlic, celery and carrot. Cook for 5 minutes. If they start to brown, turn the head down a little.
Add the boiling water, vegetable stock pot, and canned tomatoes. Stir.
Bring to the boil, then reduce to a simmer.
In a large bowl, mix together the beef mince, two-thirds of the oregano, three-quarters of the parmesan, the chili flakes, a pinch of salt and a few grinds of black pepper.
Roll the meat mixture into small meatballs about 2.5cm/1".
Add the large conchiglioni pasta shells to the soup. Cook for about 12 minutes until al dente.
While the soup is cooking, heat a drizzle of olive oil in a frying pan on medium-high heat.
Add the meatballs (polpetti). Cook for 5-7 minutes until completely browned on the outside. Be careful not to break them.
Once browned, add the polpetti to the soup for the last 5 minutes of cooking time. The meatballs are cooked when they are no longer pink in the middle.
If using, slice ciabatta in half and warm in the oven for 5 minutes.
Serve the soup in bowls and sprinkle with the remaining parmesan and oregano. Enjoy with the warm bread on the side.