Make the dough:
Mix: In a large bowl, whisk together the flour, sugar, salt, and yeast. Add the yogurt and warm water. Mix with a wooden spoon until a shaggy dough forms.
Knead: Turn it out onto a lightly floured surface and knead for 5-7 minutes until smooth and slightly tacky. (Photo tip: The dough should look smooth and spring back when you poke it. If it's sticking to your hands, dust with a little more flour.)
Rise: Place the dough in a lightly oiled bowl, cover with plastic wrap or a damp kitchen towel, and let rise in a warm spot for 1 hour, until doubled in size.
Make the garlic butter: While the dough rises, melt the butter in a small saucepan. Add the minced garlic and cook over low heat for 1-2 minutes until fragrant but not brown. Set aside. Stir in the chopped cilantro right before you're ready to brush.
Shape: Punch down the dough and divide it into 8 equal pieces (about 85g each). On a lightly floured surface, roll each piece into a rough oval or teardrop shape, about 1/8-inch thick. (I'm not a perfectionist here — rustic naan looks more authentic anyway.)
Cook: Heat your cast iron skillet over high heat for 5 minutes. Working one at a time, carefully lay the rolled naan into the hot dry skillet. Cook for 1-2 minutes, until large bubbles form on the surface and the bottom is deeply browned and charred. Flip and cook for another 30-60 seconds. (Photo tip: If it's not bubbling, you didn't wait for the pan to get hot enough. Patience!)
Finish: As soon as you flip it, brush the cooked side generously with the garlic butter. Transfer to a plate and cover loosely with foil to keep warm while you cook the remaining pieces. Repeat with all the naan.