One very easy method. Add paani puri masaala in water. Add paste of fresh pudina. Add green chilli paste. Add Aamchur powder and jaggery. ( you can add imli chutani. You get it ready made) but aamchur powder tastes equally good. Your water is ready. Boil potato, mash it. Soak chana over night. Steam it adding salt. I prefer moong instead of chana as they are easy to digest. We have elder ppl too in family who love paani poori.