Put the milk in a bowl. Add 1tsp sugar and the yeast. Stir to mix. Set aside for 15-20 minutes or until the yeast has dissolved and the mixture is frothy.
Sift the flour, salt and baking powder into a bowl. Add the remaining 1tsp sugar, the yeast mixture, 2tblsp vegetable oil and yogurt and egg. Mix to form a ball of dough.
Knead for 10 minutes until smooth and satiny (I did this in a stand mixer). Form into a ball. Pour 1/4tsp oil into a large bowl and roll the ball of dough in it. Cover the bowl with clingfilm and set aside for 1 hour until doubled in size.
Preheat the oven to it's hottest temperature. Put your heaviest baking tray to heat in the oven. Preheat your grill.
Punch down the dough and knead again. Divide into six equal balls. Keep covered when not working with the balls of dough. Roll the ball of dough into a tear-shaped naan, about 25cm long and 13cm wide at it's widest point.
Remove the tray from the oven and slap a naan on it. Put in the oven for 3 minutes, it will puff up. Now place the tray under the grill for about 30 seconds to brown slightly (I didn't bother with this as my naan browned in the oven). Wrap the naans in a tea towel or foil. Make all the naans this way. Serve hot.
I kept them warm wrapped in foil in a turned off but warm oven, you can reheat them in the microwave for 40 seconds or so.