Italian Meatball Soup

Name: Italian Meatball Soup
Ingredients: 12 ounces ground beef; 1/2 cup freshly grated Parmesan, plus more for serving; 1/4 cup plus 3 tablespoons minced fresh parsley; 2 teaspoons lemon juice; 1/4 teaspoon ground oregano; 2 cloves garlic; 1 large egg; Kosher salt and freshly ground black pepper; 3 tablespoons olive oil; 7 cups low-sodium beef stock; 2 heaping tablespoons tomato paste; 1 teaspoon peppercorns; 2 bay leaves; 1 cup diced russet potatoes (not peeled); 3/4 cup diced carrots; 3/4 cup diced celery; 3/4 cup diced onions; 8 ounces regular white cabbage, sliced; 1 loaf crusty bread, for serving