Mix turkey, egg, panko, parmesan, garlic, Italian seasoning, parsley, salt and pepper just until combined.
Roll into 1-inch meatballs (about 36 to 40) and chill while you start the soup.
Heat oil in a large pot over medium heat. Cook onion, carrots and celery 5 to 6 minutes, then add garlic for 30 seconds.
Add broth, potatoes, Italian seasoning and bay leaf. Bring to a boil, then reduce to a gentle simmer.
Drop in the meatballs and simmer 10 minutes without stirring for the first 5 minutes.
Stir in the shell pasta and simmer 8 to 10 minutes until the pasta and potatoes are tender and meatballs reach 165°F.
Stir in the peas for 2 minutes, remove the bay leaf, season and finish with lemon, parsley and parmesan.