BAs Best Matzo Ball Soup

Name: BA's Best Matzo Ball Soup
Ingredients: 6 large eggs; ½ cup melted schmaltz (chicken fat) or vegetable oil; 6 Tbsp. low-sodium chicken broth or water; 3 Tbsp. chopped dill; 1½ tsp. kosher salt; ¾ tsp. freshly ground black pepper; 1½ cups matzo meal; 4 chicken legs (thigh and drumstick; about 3 lb.); 1½ tsp. plus 3 Tbsp. kosher salt; plus more; 6 lb. chicken wings; 2 medium onions, peeled, halved; 2 celery stalks, cut into 2 pieces; 1 medium parsnip, peeled, cut into 2 pieces; 3 medium carrots, peeled, 1 cut into 2 pieces, 2 thinly sliced; 1 bunch parsley; 1 Tbsp. black peppercorns; Chopped dill (for serving); Freshly ground black pepper