In a bowl, combine the all-purpose flour, whole wheat flour, baking powder, salt, and sugar. Mix well. Add the yogurt and mix again. Then add the milk and knead into a dough. If needed, add water to make a soft dough. Cover and let it rest for 2 hours.

Heat a skillet well. Take one dough ball and roll it out to your preferred thickness. Sprinkle some nigella seeds on top and press them in. Brush the other side with water and place it water-side down on the skillet. Press gently. When one side is golden brown, flip the skillet to cook the other side until golden. Brush with butter and serve hot with dal makhani or any curry.