In a large bowl, combine ground turkey, Panko, Parmesan, garlic, basil, and red pepper flakes, if using; season with salt and pepper, to taste. Using a wooden spoon or clean hands, stir until well combined. Roll the mixture into 3/4-to-1-inch meatballs, forming about 30-32 meatballs.
Heat 1 tablespoon olive oil in a large stockpot or Dutch oven over medium heat. Add meatballs, in batches, and cook until all sides are browned, about 2-3 minutes. Transfer to a paper towel-lined plate; set aside.
Add remaining 1 tablespoon oil to the stockpot. Add garlic, onion, carrots and celery. Cook, stirring occasionally, until tender, about 3-4 minutes. Stir in thyme until fragrant, about 1 minute.
Whisk in chicken stock and bay leaves; bring to a boil. Stir in pasta and meatballs; reduce heat and simmer until pasta is tender and meatballs are cooked through, about 10-12 minutes.
Stir in zucchini and spinach until the spinach has wilted, about 2 minutes.
Stir in lemon juice and parsley; season with salt and pepper, to taste.
Serve immediately.
Notes
Use your favorite meat. Ground pork, beef, chicken or turkey will all work very well here for the meatballs.
Don't overwork the meatballs. Using your hands (or a wooden spoon, but preferably hands), combine the meatballs just until combined. Overmixing will yield tough turkey meatballs!
Prep the meatballs ahead of time. The meatballs can be assembled up to 1 day in advance or stored in the freezer for long term storage. For a quicker shortcut, substitute frozen mini meatballs (I personally love Trader Joe’s party size mini meatballs – a huge guilty pleasure of mine!).
Add a splash of wine. Add a splash of white wine when sautéing the aromatics to create a quick restaurant-quality soup! It is a great way to deglaze the pan from the meatballs and to add bright, rich flavors. Opt for pinot grigio or sauvignon blanc (never using cooking wine), letting it reduce by half (about 1-2 minutes).
Use good-quality stock. The better quality your stock, the better your soup. Many brands love to pack in the salt so always opt for unsalted or a lower-sodium variety. Homemade stock is even better.
Add in leafy greens. This is a great recipe to sneak in leafy greens for those picky eaters. Spinach, kale, collard greens, swiss chard, or arugula are all great options.
Freeze as needed. This soup freezes beautifully but if you plan to freeze, cook the veggies slightly firm so they can hold up during freezing and reheating.