Add oil to a pan. Then add one sliced onion, 1/2 cup of desiccated coconut and 1/2 teaspoon of turmeric. Sauté on medium flame till coconut is lightly browned. This should take about a couple of minutes. Transfer the contents to a blender and add 3 teaspoons of garam masala and a cup of water. Blend till it's a smooth consistency, not too runny not too thick. Set aside.

In a pot, add oil. Then add the diced onions and sauté till transparent. Add tomatoes, 1/2 teaspoon each of turmeric and chilli powders and sauté on low flame till tomatoes have softened.

Add the coconut-onion blended mix to the pot and let it simmer for a couple minutes. Now add the cooked beans and about 1.5 cup water. (When adding this water I put it in the blender first to avoid wasting the masala stuck to the blender). It shouldn't be too thick. Add sugar and stir well. Add salt according to taste.

Add curry leaves and let it simmer till curry thickens. This takes about 10-12 minutes. It shouldn't be watery. (When I don't have curry leaves on hand I just skip the step as it isn't easy to find. Although the curry leaves impart a great flavour to the dish, the dish tastes good without it as well)

Add cilantro and stir well. After a minute, switch off the flame. Your curry is ready!