Soak the lobia overnight or for a few hours. drain and rinse the lobia with water. again drain and keep aside. in a pressure cooker or pressure pan, heat oil. add the cumin seeds and let them sizzle. then add the chopped onions. stir and saute till the onions become translucent. add the chopped ginger, garlic and green chilies. saute till the raw aroma of the ginger and garlic goes away. then add the chopped tomatoes and stir. next add the all the dry spices - turmeric powder, red chili powder, coriander powder and garam masala. stir and saute the masala on a low flame, till the tomatoes become soft and the entire tomato-onion mixture starts to leave the sides of the pan or cooker and you see the oil leaving from the sides. this cooking method is called as bhunao in punjabi and takes some time. now add the lobia or black eyed beans. stir well. then add 3 cups water.add salt. stir pressure cook till the lobia is cooked completely. i cooked it for 8-9 whistles as I had soaked it for only half an hour. if you have soaked it overnight or for 2-3 hours, it will take less time to cook. the lobia should be soft enough and when pressed with your fingers, it should get mashed easily. check the lobia once its done. once the lobia beans are cooked, simmer the gravy without the lid so that it gets thickened. you can also mash a few cooked beans to thicken the gravy. the consistency of the lobia masala gravy is neither thin nor thick. lastly add 2 tbsp chopped coriander leaves and give a final stir. you could also garnish lobia masala with chopped coriander leaves. serve punjabi lobia masala with rotis or steamed rice.