For the Fermented Herbs

• ¹⁄₂ cup roughly chopped basil leaves and stems
• ¹⁄₂ cup roughly chopped dill leaves and stems
• ¹⁄₂ cup roughly chopped flat-leaf parsley leaves and stems
• 1 ¹⁄₂ tsp. kosher salt

For the Broth and Turkey Meatballs

• 2 small yellow onions
• 1 lb. ground turkey
• Kosher salt and freshly ground black pepper
• 1 tbsp. unsalted butter
• 1 small carrot
• 1 lb. Yukon gold potatoes, peeled and cut into 1/2-inch cubes
• 1 bay leaf

Instructions

1. Make the fermented herbs: In a medium bowl, toss the basil with the dill, parsley, and salt until evenly combined. Cover the herbs with a square of cheesecloth and weight with a plate small enough to fit over the herbs but not touch the sides of the bowl. Place a heavy can or weight on the plate and refrigerate the herbs. After 24 hours, remove the weights and rinse and wring out the cheesecloth. Replace the cheesecloth and weights over the herbs and repeat once a day for 4 more days. After the fifth day, remove the weights, discard the cheesecloth, and scrape the herbs into a small jar. Seal the jar and refrigerate the herbs until ready to use, or up to 2 weeks.
2. Make the meatballs and broth: Using the large holes of a box grater, grate 1 onion into a large bowl and add 1 tablespoon of the fermented herbs and the turkey meat. Season the meat with salt and pepper and, using your hands, mix until evenly combined. Using a tablespoon measure, portion the meat into about 3 dozen ¹⁄₂-oz. meatballs.
3. In a large saucepan, heat the butter over medium. Finely chop the remaining onion and finely grate the carrot. Add both to the pan and cook, stirring, until softened, 5 minutes. Add the potatoes, bay leaf, and 8 cups water and bring to a boil. Reduce the heat to maintain a steady simmer and cook for 5 minutes. Add the meatballs and cook until the meatballs and potatoes are tender, about 10 minutes. Ladle the meatballs, vegetables, and broth into soup bowls and serve with the fermented herbs on the side, using them as a seasoning instead of salt.