Chicken matzo ball soup

Name: Chicken matzo ball soup
Ingredients: 1 chicken with extra giblets (use kosher chicken, if you like); 3 chicken stock cubes (use kosher stock, if you like); 1 bay leaf; 10 peppercorns; 4 carrots, sliced; 2 onions, peeled, root intact; 2 celery sticks, sliced; 1 swede, peeled and cut into chunks; ½ small pack parsley, roughly chopped; challah bread, to serve (optional); 1 ½ tbsp fat from the chicken soup; 1 egg, beaten; 100g matzo meal