Add the warm water and sugar to small bowl. Stir to dissolve the sugar.
Sprinkle the yeast over the top of the water. Let it sit until foamy, about 5-10 minutes.
Combine the flour and salt in a separate large bowl.
Add the yeast mixture, yogurt, and olive oil to the flour. Mix to form a soft dough. Add more flour if too sticky.
Knead on a floured surface for 5-7 minutes until smooth and elastic (or in a stand mixer for 3-4 minutes).
Place in an oiled bowl, cover, and let rise in a warm place until doubled, about 1 hour.
Punch down the dough, and divide into 10 equal pieces.
Roll each into a ball.
Flatten and roll each into a circle about 1/4 inch thick.
Cook each flatbread in a lightly oiled skillet over medium-high heat for 1-2 minutes per side, until puffy and golden brown.
Notes
Warm water: It's important that the water be at the correct temperature. If the water is too hot, it can kill the yeast. If it's too cool, it can slow the rising time.
Active dry yeast: You can also use an equal amount of instant yeast in place of the active dry yeast. There's no proofing required when using instant yeast.
All-purpose flour: For chewier flatbread, you can use bread flour in place of all-purpose flour.
Yogurt: I use plain yogurt, not plain Greek yogurt in this recipe.