Spring Chicken Soup with Matzo Balls

Name: Spring Chicken Soup with Matzo Balls
Ingredients: 3 medium leeks (about 1 1/2 pounds), top 2 inches of dark green parts discarded, then halved lengthwise and cut crosswise into thirds; 5 large carrots (about 1 pound), cut into thirds; 2 celery ribs, cut into thirds; 1 (4- to 4-1/2 pound) chicken (giblets and liver removed); 1 small head garlic, halved crosswise; 1/3 cup sliced fresh ginger (unpeeled but skin scrubbed); from one 1/2-ounce piece; 15 long fresh flat leaf parsley stems; 15 long fresh dill stems; 12 black peppercorns; 1 tablespoon kosher salt; 4 quarts cold water; 1 cup matzo meal, plus 1 tablespoon; 1/3 cup finely chopped flat leaf parsley; 3 tablespoons finely chopped fresh dill; 3 tablespoons rendered chicken fat; 1/2 cup chicken broth (reserved from recipe below); 4 large eggs, separated; Dill sprigs for garnish