Naan is a popular Indian flat bread cooked using 'tandoor' or clay oven. It is easily obtainable from North Indian restaurant almost all countries around the world.
It is made using plain flour, dry yeast and yogurt then left to ferment for several hours before baking them.
However, you could prepare your own using the oven. But now I'm using flat pan to cook them. In fact you can make very good naan from white bread dough or pizza recipe. Besides spicy gravy, you can also serve them with soups or dips.