Bring a large pot to a boil. Add 1 tsp salt and 1 tsp chicken stock. If you add the chicken into the boiling water, the skin is most likely to tear because of temperature shock. So you can either add the chicken into the water and slowly bring to a boil. Or if using boiling water, ladle the hot water all over the skin to tighten it first. Then submerge the chicken into the water. Make sure the water is enough to fully cover it. Keep the water boiling for 5-7 minutes first. Then cover the lid, turn off the heat and leave for 15 minutes. If you prefer softer chicken, keep it in the pot for another 15-30 minutes.