Wash and soak chana dal for 1 to 1½ hour. Drain completely.
Cut cabbage to quarters and remove the core. Dip them in hot water and leave it for 5 mins. Drain and rinse well in fresh water in a pot. Drain completely and shred the cabbage and chop to very small size bits.
Add the cabbage to a mixing bowl along with coriander leaves, salt, green chili, ginger, curry leaves and ¼ cup soaked chana dal.
Pulse the remaining chana dal to a coarse mixture without adding any water.
Add this to the cabbage mixture along with garam masala and red chili powder.
Mix this well and set aside for 10 minutes.
Add 2 tbsp. rice flour and mix. If needed you will have to add another tbsp. flour if the dough doesn't bind well.
Take small portion of this mixture and check if it can be formed to a ball. It has to bind well else add another tbsp. flour and mix.
Making cabbage vada
Heat oil until hot enough. Divide the dough to 10 to 12 portions and make round balls. Flatten them and drop to hot oil. You can make the cabbage vada on a greased foil or cling film. You can also make it directly in your palm and shape them.
Fry until golden stirring often on a medium heat.
Drain them to kitchen tissues. Fry the cabbage vada in batches of 2 to 3.
Serve cabbage vada with a cup of tea or canny chutney.