In a small bowl, combine the warm water, sugar, and yeast. Give it a gentle stir, then cover the bowl and let it stand for about 10 minutes. The mixture should become foamy, which indicates that the yeast is active. If it doesn’t foam, your yeast may no longer be active, and you should start over with fresh yeast.
In a large bowl, whisk together the flour and salt. In a separate bowl, whisk the milk and egg together. Create a well in the center of the flour mixture and pour in the foamy yeast mixture, the melted ghee or butter, and the milk and egg mixture. Use a spatula or wooden spoon to mix everything until a shaggy dough forms. Then, use your hands to bring the dough together into a ball.
Cover the bowl with plastic wrap or a damp kitchen towel. Place the bowl in a warm, draft-free spot and let the dough rise for 1 to 1.5 hours, or until it has doubled in size.
Once the dough has risen, gently punch it down to release the air. Transfer the dough to a lightly floured surface and divide it into 6 equal portions. Roll each portion into a smooth ball.
Place the dough balls on a floured plate or baking sheet. Cover them loosely with a clean kitchen towel and let them rest for another 15 minutes. They should puff up slightly.
Take one dough ball and flatten it with your hand. On a lightly floured surface, use a rolling pin to roll it out into a thin oval or round shape, about 1/8-inch thick. Repeat with the remaining dough balls.
Heat a cast-iron skillet or a heavy-bottomed non-stick pan over medium-high heat until it is very hot. You can test if it’s ready by flicking a drop of water onto the surface; it should sizzle and evaporate immediately. Place a rolled-out naan onto the hot, dry skillet. Cook for 1 to 1.5 minutes, or until large bubbles start to form on the surface and the bottom has golden-brown spots.
Flip the naan and cook for another 1-2 minutes on the other side, until it’s cooked through and has light brown spots.
Remove the naan from the skillet and immediately brush it with the melted ghee or garlic butter. Sprinkle with nigella seeds and fresh cilantro, if desired. It’s best to serve the naan warm.