Preheat your waffle iron.
In a mixing bowl, combine the mashed rajma, besan, yogurt, chopped onion, tomato, cilantro, ginger-garlic paste, cumin powder, coriander powder, turmeric powder, red chili powder, and salt. Mix well.
Add baking soda to the batter and mix until well combined.
Grease the waffle iron with a bit of oil.
Spoon the batter onto the preheated waffle iron, spreading it evenly.
Close the waffle iron and cook until the waffles are golden brown and crisp.
Repeat with the remaining batter.
Serve the Rajma Waffles hot with your favorite chutney or yogurt on the side.