In a large mixing bowl, combine the ground chicken, egg, pecorino romano, minced garlic, dried basil, dried parsley, salt, black pepper, and panko breadcrumbs. Mix until just combined — do not overwork. Roll into 1-inch (2.5cm) meatballs using a small cookie scoop or tablespoon for consistent sizing. You should get approximately 24-28 meatballs.

Heat a large heavy-bottomed pot or Dutch oven over medium heat and add 1 tablespoon of the canola oil. Add the chopped onion with a pinch of salt and stir to coat. Cook until soft and translucent, about 5 minutes. Add the spinach and minced garlic, stirring constantly until the spinach wilts, about 1-2 minutes. Transfer the onion and spinach mixture to a bowl and set aside.

With the heat still on medium, add the remaining 1½ tablespoons canola oil to the pot. Working in batches if needed to avoid crowding, add the meatballs and cook for 2 to 3 minutes per side until lightly browned. The meatballs do not need to be cooked through — they will finish cooking in the broth.

Return the onion and spinach mixture to the pot with the browned meatballs. Add the chicken stock, water, and diced tomatoes. Stir gently.

Stir gently and bring to a boil. Reduce heat to a low simmer and cook for 20 minutes, until the meatballs are cooked through and reach an internal temperature of 165°F / 74°C. Add the ditalini pasta and grated Parmesan, stir to combine, and cook for 8 to 10 minutes more until the pasta is al dente. Taste and adjust seasoning with salt and pepper as needed. Ladle into bowls and serve hot.