In a bowl, combine ground turkey, beaten eggs, oats, Parmesan cheese, garlic, oregano, mustard, salt, and pepper.
Shape the mixture into 25–30 meatballs and place them on a parchment-lined baking sheet.
Refrigerate while preparing the soup to firm them up for easier handling.
Soup:
In a Dutch oven, heat the olive oil over medium heat. Sauté the onion and garlic until softened (about 3 minutes).
Add the carrots and celery, and cook while stirring frequently for 4 minutes.
Stir in chicken broth, strained tomatoes, fleur de sel, sugar, and pepper. Bring to a boil, then reduce the heat and simmer for 7 minutes.
Add the vermicelli and turkey meatballs to the soup. Bring it back to a boil, then reduce heat to medium, and gently simmer, stirring occasionally, until the pasta is al dente and the meatballs are cooked through, about 10 minutes.
Just before serving, stir in the frozen peas and remove the pot from heat. Let stand for 1 minute.
