Wash black chana with water, soak in water for 8-10 hours. After 10 hours, take out all the water from soaked chana and keep aside.
Heat 2 tbsp oil in a pressure cooker, crackle cumin seeds, add bay leaf, onion and green chili, cook on medium flame, add ginger –garlic paste and cook for a minute. Add red chili powder, coriander powder, turmeric powder, salt and mix. Add chopped tomatoes, potatoes, and soaked chana. Cook for a minute, add 500ml water, mix and cover the cooker with lid, take 6-7 whistles on medium flame. Switch off the flame, let it cool for some time. Open the pressure cooker, mix and press some chana and aloo pieces, add garam masala and fresh coriander, mix and cover the pressure cooker with lid and keep aside.
For hing ajawayan paratha, mix all spices and oil in a bowl. Take a portion from the dough, make a ball, cover with dry flour. Roll in a small, thick disc. Apply prepared oily masala on the disc, fold the disc in half, apply oily masala on half folded disc, now again fold the half disc and make a quarter. Cover with dry flour, and gently roll with a rolling pin. Put rolled paratha on medium hot tawa, roast from both sides on low flame, apply oil both sides, rost for few seconds and our masaledar hing ajwayan paratha is ready.
Serve hot parathas with spicy chana sabji