Combine Meatball Ingredients: In a sizable bowl, mix together the ground beef and pork. Incorporate bread crumbs, parsley, oregano, parmesan, an egg, salt, and pepper thoroughly by hand for an even mixture.
Shape the Meatballs: Roll the mixture into small, uniform meatballs, about the size of 3/4 to 1 inch, arranging them on a plate once shaped.
Brown the Meatballs: In a skillet with 1 Tbsp olive oil over medium-high heat, brown the meatballs in batches until they're evenly golden, about 4 minutes, then place them on a plate lined with paper towels.
Prep the Veggies: Heat another tablespoon of olive oil in a pot. Cook the carrots, onions, and celery until they're softened, about 6-8 minutes, then add garlic and cook for a minute more.
Cook the Soup: Add chicken broth to the pot, seasoning with salt and pepper. Bring to a boil, then add the meatballs and pasta, reducing the heat to a simmer. Cover and cook, stirring occasionally, until the pasta is al dente and the meatballs are cooked through, about 10 minutes. Add spinach in the final minute.
Finish and Serve: Ladle the soup into bowls, garnishing with parmesan cheese. Serve hot for a comforting and satisfying meal.