Winter Vegetable Soup with Turkish Meatballs

Name: Winter Vegetable Soup with Turkish Meatballs
Ingredients: 3 tablespoons extra-virgin olive oil; 2 medium leeks, white and pale green parts only, halved lengthwise, rinsed and thinly sliced; 3 medium onions, coarsely chopped; 5 cloves garlic, chopped; 6 medium carrots, thinly sliced; 4 stalks celery, thinly sliced; 3 medium parsnips, peeled and thinly sliced; 1 ½ teaspoons kosher salt; 1 teaspoon ground pepper; 1 pound potatoes, peeled and cut into 1/2-inch pieces; 1 ½ cups canned crushed tomatoes; 1 ½ tablespoons chopped fresh thyme; 8 cups low-sodium chicken broth