Boil chicken, bones and/or turkey necks covered with water in a 10-quart soup pot. Clean the fat from soup. When you see a brown and white foam come to the top, spill off the water into the sink. Rinse both the pot and the chicken, meat or bones well. Or, carefully spoon out the foam after the water comes to a high boil.
Place the chicken/bones/necks and prepared vegetables, except for the zucchini and potatoes, in the pot. Add herbs and spices and cover with cold water plus 3 cups. Bring to a boil. Cook covered over medium-low heat for about 2 hours. Add the zucchini and potatoes in the last hour of cooking.
Place a slice of dry bread in cheesecloth and float it on top toward the end of cooking. Discard when the fat is soaked up or float a lettuce leaf on top toward the end of cooking, discarding it when done.