In a small bowl, combine 1/2 cup of warm water, 1 teaspoon of sugar, and 1/4 oz (7g) of active dry yeast. Stir gently and let it sit for about 5-10 minutes until it becomes frothy.
In a large mixing bowl, combine 2 1/4 cups of all-purpose flour and 1 teaspoon of salt. Mix well to combine.
Add the frothy yeast mixture and 1/2 cup of plain Greek yogurt to the flour mixture. Also, add 1 tablespoon of vegetable oil. Mix until a dough starts to form.
On a lightly floured surface, knead the dough for about 5-7 minutes until it becomes smooth and elastic.
Place the kneaded dough in a lightly greased bowl, cover it with a kitchen towel, and let it rise in a warm place for about 1-2 hours, or until it has doubled in size.
While the dough is rising, melt 4 tablespoons of salted butter in a small bowl. Add the finely minced garlic and stir to combine.
Once the dough has risen, punch it down to release the air. Divide the dough into 6 equal portions and shape each portion into a ball.
Heat a skillet or griddle over medium-high heat and lightly grease it with oil. Place one rolled-out naan in the skillet and cook for about 1-2 minutes until bubbles form on the surface.
Once cooked, remove the naan from the skillet and immediately brush it with the garlic butter mixture. Sprinkle with chopped cilantro leaves.
Repeat the cooking process with the remaining naan dough, greasing the skillet as needed.