In a mixing bowl, combine flour, yeast, sugar, and salt. Mix well.
Add yogurt and warm water to the bowl and mix everything together.
Knead the dough for 8-10 minutes until it becomes soft and smooth.
Cover the dough and let it rest for 1 hour
Preheat the tandoor or oven to 500°F (260°C)
Divide the dough into 4 equal parts
Roll each part into an oval shape of about 1/4 inch thickness
In a small bowl, mix vegetable oil, nigella seeds, and chopped cilantro
Brush the top of each naan with the oil mixture
Place the naan in the tandoor or oven and bake for 2-3 minutes until it becomes golden brown on top
Flip the naan over and bake for another 1-2 minutes until it becomes golden brown on the other side
Remove the naan from the oven and brush it with some butter (optional)
Remove the naan from the oven and brush it with some butter (optional).Serve hot