In a small bowl, soak chana dal in water for at least 1 hour. Drain the water and transfer the soaked dal to the blender. Add cumin & coriander seeds, green chilies, ginger and coconut. Blend into a coarse mixture adding very little water.
½ cup Chana dal, rinsed and drained, 1¼ cup Water, plus more for blending the masala, 2 teaspoons Cumin seeds, 2 tablespoons Coriander seeds, 4 Green chilies, 1" Ginger piece, chopped, 2 tablespoons Fresh or dry grated coconut