Preheat the oven to 400 degrees F.
FOR THE CHIMICHURRI
Combine the parsley, basil, mint, and garlic in a food processor (or finely chop ingredients and mix in a large bowl).
Add the vinegar and oil and stir or pulse the food processor a few times to combine.
Season to taste with salt and pepper.
FOR THE MEATBALLS
In a large bowl, combine the onion, garlic, parsley, basil, egg, breadcrumbs, Parmesan, oregano, thyme, salt, and pepper. Using a large spoon, stir to blend. Add the ground turkey and stir until ingredients are thoroughly combined.
Form the meatballs into 1 1/2-inch balls. Place the meatballs on a large baking sheet, spacing 1-inch apart.
Bake until cooked through, 25 minutes.
Serve with chimichurri.