Put ginger and garlic into a food processor and add 1/2 cup water. Blend until fairly smooth.
Heat the oil in a wide, heavy saucepan over a medium flame. When hot, put in the cumin seeds. Stir for half a minute.
Pour in the ginger-garlic paste. Stir and cook for about two minutes. Put in the coriander and stir a few times.
Put in the chopped tomatoes. Stir and cook for 2 minutes mashing the tomato pieces with the back of a slotted spoon.
Put in the beans and salt and one cup of water. Bring to simmer.
Cover, turn heat to low and cook for 8-10 minutes or until the beans are tender enough.
Remove the cover. Add the lemon juice and a generous amount of freshly ground pepper.
Turn up the heat and boil away the remaining liquid, stirring the beans gently as you do so.
Recipe By : Somesh Rao