Add 1 cup of roasted black chickpeas (kala chana) into a mixing bowl. (Optionally dry roast for 2 minutes if needed for extra crunch).
Add finely chopped cucumber, onion, tomato, green chilies, and fresh coriander to the bowl.
Sprinkle regular salt, black salt, chaat masala, and roasted cumin powder.
Squeeze fresh juice of half a lemon over the mixture.
Mix thoroughly to combine all the spices and veggies evenly. Serve fresh immediately!