Wash and soak lobia or black eyed peas for 6 – 8 hours, or overnight.
Heat oil in a medium sized saucepan, and add sliced onions. Fry the onions, and cook till light golden brown.
Add garlic paste, followed by coriander powder, red chili powder, turmeric powder and salt. Stir and cook for a minute till the spices release their aroma.
Add the chopped tomatoes, and cook for 5 – 8 minutes till they soften and oil starts releasing. Use a wooden spoon to mash the tomatoes.
Drain the soaked lobia / black eyed peas, and add to the onion – tomato mixture. Stir together, and cook for a few minutes.
Add about 1 – 1 ½ cups water, and bring to a boil. Once the mixture comes to a boil, turn heat to low, and cook for about 30 – 40 minutes till the lobia / black eyed peas are tender. The water will have evaporated, and you will be left with a thick gravy. Adjust the water content based on how gravy is preferred.
Garnish with coriander / cilantro leaves, and green chilies. Serve hot with roti / chapati, naan or Basmati rice.