Rince the dal and remove any debris. Combine the dal and 6 cups of the water in the slow cooker.
In a medium size skillet, melt the butter over medium heat. Add the ground spices, cook 1-2 minutes, stirring constantly, just to heat and gently toast them. Stir into the dal and add the bay leaf. Cover and cook on LOW for 4 to 5 hours. The mixture will be soupy.
In a blender or small food processor, combine the ginger, coconut, cilantro, and remaining 1/2 cup of water and process until smooth. Add to the cooker along with the rice, cover, and cook on LOW until the rice is tender, 1 to 1 1/2 hours longer.
Remove the bay leaf and season with salt. Serve the soup hot in bowls with some warm whole wheat tortillas or chapatis.