Mix warm water, yeast, and a little sugar; let sit until foamy
Add flour, salt, yogurt, and oil to make a soft dough
Knead until smooth and elastic
Cover and let the dough rise until doubled
Divide the dough into equal portions
Roll each portion into an oval or round shape
Heat a skillet, griddle, or tandoor until very hot
Cook each naan on one side until bubbles form
Flip and cook the other side until browned
Brush with melted butter or ghee
Serve warm