Combine the warm water, active dry yeast and sugar in a medium size bowl. Let sit for about 10 minutes, or until it foamy and has puffed up. Add the yogurt, olive oil and salt to the yeast. Stir just until combined.
Place the flour in a large bowl. Create a well in the middle. Add the wet ingredients to the middle. Stir until it becomes to hard to stir. Then knead the dough with your hands. You may also use an electric mixer with a dough hook. Knead for 3-5 minutes. Form the dough into a ball and place in a greased bowl. Cover with a clean kitchen towel or plastic wrap. Allow to rise for 1 hour in a warm place, or until doubled in size.
Punch down the dough and divide the dough into eight pieces (about 75 g each). Shape each piece into a ball and then cover with a damp paper towel for 10-15 minutes.
Roll out one piece of dough at a time on a lightly floured surface. Roll into an circle about 1/8" thick.
Brush about 1/2 teaspoon oil onto a large cast iron skillet. Heat over medium heat. Place rolled out dough onto the pan once it's hot and allow to cook for 1-2 minutes. Once it has puffed up with bubbles across the top, flip to the other side and cook an additional minute or until you see golden brown spots. Remove to a plate and cover with a towel.
Brush the warm naan with melted butter. Best served warm and fresh. Will keep for 1-2 days in an airtight container at room temp.
Notes
Freezer instructions: Place in a zip top freezer bag with a piece of parchment in between each piece. Store in the freezer for up to 3 months. Simply reheat in a damp towel.