Wash and clean beet leaves and then blanch them in hot water. Once it cools down, transfer to a blender and blitz to make a puree. Add little water if required. Keep it aside for now. In a mixing bowl, add amaranth flour, oats powder, semolina, salt, beet leaves puree, cumin seeds, sesame seeds, chilly powder and grated potatoes. Add enough water to give it a thick pouring batter consistency. Before you start making the idli, add baking soda to the mix.