Put the flour into a large bowl and add the salt and sugar. Mix well with either a fork or a spatula.
3 cups all-purpose flour, 1 tsp salt, 1 tsp sugar
Now we add the yogurt and active sourdough starter. (Please see the notes on how to activate your sourdough starter.)Mix in well. 1/2 cup full-fat yogurt, e.g Greek yogurt, 1/2 cup active sourdough starter
Gradually add the water. Use your hands to incorporate the flour while you are adding the water. Note: The dough will seem quite dry, but don't feel tempted to add more water. After a while, the dough will become a bit sticky. 1/2 cup filtered water
Knead the dough for a couple of minutes. Cover the dough with cling wrap and let it rest for an hour. After an hour, knead the dough again for 2 minutes until it feels soft and elastic.
Cover the dough and leave it in a warm place to bulk ferment until it has doubled in size. (It can take from 4 to 6 hours, depending on the temperature in your kitchen.)
Once the dough has doubled in size, dust your workbench with flour and tip out the dough. Form the dough into a ball and divide the dough into 12 pieces (around 50 grams each).
extra flour for dusting
Form each dough piece into a ball and cover them to rest for 20 minutes.
Roll each dough ball with a rolling pin into either an oval or round shape (depending on your griddle). You want them quite thin.
Heat your cast-iron griddle and place the naan bread in. Cook on each side on medium heat for about 2 minutes or until golden brown.Note: The naan bread will puff up while cooking. You can press it down with a spatula or fork. Once the naan bread is cooked, place it on tin foil and immediately top with garlic butter and chopped coriander (optional). (See notes for more details.)
Wrap the naan bread in tin foil to keep it warm.
Enjoy with your favorite curry or just on its own.