Lemony Lamb Meatball Soup with Rice

Name: Lemony Lamb Meatball Soup with Rice
Ingredients: 1 pound ground lamb; ¼ cup milk; 3 tablespoons panko bread crumbs; 2 tablespoons minced fresh dill , divided; 2 teaspoons grated lemon zest plus 2 tablespoons juice; 1½ teaspoons table salt , divided; ½ teaspoon pepper; 2 tablespoons extra-virgin olive oil , plus extra for serving; 1 pound leeks , white and light green parts only, halved lengthwise, sliced ½ inch thick, and washed thoroughly; 8 cups chicken broth; ¾ cup long-grain white rice