Put the milk in a bowl. Add 1 teaspoon of the sugar and the yeast. Stir to combine. Set aside for 15 to 20 minutes or until the yeast has dissolved and the mixture is frothy.
Sieve the flour, salt and baking powder into a large bowl. Add the remaining teaspoon sugar, the yeast mixture, 2 tablespoons vegetable oil, yoghurt and egg. Mix and form a ball of dough. Place the ball of dough onto a work surface and knead it for 10 minutes or more until it is smooth and satiny. Form into a ball. Pour a little oil into a large bowl and roll the ball of dough in it. Cover the bowl with a piece of cling film and set aside in a warm place for about an hour or until the dough has doubled in size.
Preheat oven to highest temperature. Put the heaviest baking tray you own to heat in the oven. Preheat your grill.
Punch down the dough and knead it again. Divide into 6 equal balls. Working with one at a time whilst keeping the others covered, roll into a tear-shaped naan, about 25cm long and 12cm wide. Remove the hot baking tray from the oven and slap the naan onto it. It should puff up. Now place the baking tray and naan under the grill about 3 - 4 inches from the heat source for about 30 seconds or until the top of the naan browns slightly. Wrap the naan in a tea towel and work the remaining balls of dough the same way. Serve hot.