Place chicken, broth, bouillon, pepper and parsley in crockpot and cook 6 hours or overnight, until chicken is tender and can be shredded.
Using tongs, take chicken out of broth and shred using a fork in a bowl and transfer broth and shredded chicken into a large saucepan and simmer until ready to bring to a boil. Make the dumplings.
In a large bowl, whisk together the flour, salt and baking powder and make a well in the center of the flour mixture. Add the egg and a little of the warm water and start stirring with a fork and continue adding the water until your mixture is a like a sticky noodle batter. Add more flour or less water to get your rivel consistency.
Bring broth to boil, then drop dough by teaspoonfuls into the boiling soup, stirring constantly, then turn heat down so it's still bubbling but not boiling. Cook for 10-15 minutes or until rivels are cooked through.
TIP: Test to see if the rivels are done by fishing out the biggest one you can find and cutting it in half. If it still looks dry/floury on the inside, let them cook a little longer