Mix yeast with sugar and warm water in a bowl. Cover with tea towel, leave for 10 minutes until foamy.
Whisk egg and milk together.
Whisk or sift flour and salt together in a separate large bowl.
Make a well in the flour, then add yeast and egg mixture. Mix together with a spoon. Once the flour is mixed in, bring it together into a ball. No need to knead!
Cover the bowl with a damp tea towel for an hour or so to proof and double in size. If you plan on taking camping, the dough can be lightly oiled and wrapped for the next day after refrigerated or kept in a cooler.
Place dough on lightly floured surface and cut into a dozen similar sized pieces, then work each piece into a rounded ball.
Proof again on a lightly floured tray, covering with tea towel for 15 minutes or so, until risen another half size.
Prepare your equipment and heat source for cooking on a griddle or large cast iron skillet over medium-high heat.
Flatten a ball on a lightly floured cutting board. Roll out with a rolling pin until naan is approximately 3 mm thick.
Apply a light coat of oil or fat to the hot skillet or griddle and add rolled out dough. Depending on pan size, you should be able to cook 2-3 at a time.
Bubbles will form in the dough in about a minute if pan is hot enough. Flip using tongs or spatula to cook the second side after 90 seconds to two minutes total…other side should be golden.
As soon as the second side is golden brown, remove the hot cake from the pan, transfer to a plate, and brush with melted butter and sprinkle with sesame seeds if desired.
Re-grease pan and keep cooking naan flats till done.