Preheat oven to 210°C (410°F) using conventional oven settings (top and bottom heat). Peel the onion and garlic, finely dice the onion, and press it onto the garlic cloves using the flat side of a knife. Wash the carrot and celery and dice them.

Place the ground meat, egg, breadcrumbs, Parmesan cheese, oregano, and salt in a bowl and knead with your hands or a spoon until a homogeneous mixture forms. Shape the mixture into approximately 30 small meatballs and place them on a baking sheet lined with aluminum foil.

Place the meatballs in a preheated oven at 210°C (410°F) using conventional oven settings (top and bottom heat) for 10 minutes. Meanwhile, heat oil in a large, wide pot and sauté the vegetables with a generous pinch of salt over medium-high heat for 8 to 10 minutes, until the vegetables are slightly softened.

After 10 minutes, remove the meatballs from the oven and add them to the pot. Pour in the vegetable broth and bring the soup to a simmer over medium-high heat, covered. Once the soup is boiling, add the uncooked pasta. Reduce the heat slightly and let the pasta simmer in the soup for about 10 minutes (or according to package directions) until al dente, stirring regularly.

Once the pasta is cooked, turn off the stove and season the soup with salt and pepper.