In a small bowl, combine the yeast, sugar and warm water. Stir to dissolve then let sit for a few minutes or until it is frothy on top. Once frothy, whisk in the oil, yogurt, and egg until evenly combined.
In a separate medium bowl, combine 1 cup of the flour with the salt. Next, pour the bowl of wet ingredients to the flour/salt mixture and stir until well combined. Continue adding flour, a half cup at a time, until you can no longer stir it with a spoon (about 1 to 1.5 cups later).
At that point, turn the ball of dough out onto a lightly floured surface and knead the ball of dough for about 3 minutes, adding small amounts of flour as necessary to keep the dough from sticking. You'll end up using between 2.5 to 3 cups flour total. The dough should be smooth and very soft but not sticky. Avoid adding excessive amounts of flour as you knead, as this can make the dough too dry and stiff.
Loosely cover the dough and let it rise until double in size (about 1 hour). After it rises, gently flatten the dough into a disc and cut it into 8 equal pieces. Shape each piece into a small ball.
Heat a large, heavy bottomed skillet over medium heat. Working with one ball at a time, roll it out until it is about 1/4 inch thick or approximately 6 inches in diameter. Place the rolled out dough onto the hot skillet and cook until the bottom is golden brown and large bubbles have formed on the surface (see photos below). Flip the dough and cook the other side until golden brown as well. Stack the cooked flat bread on a plate and cover with a towel to keep warm as you cook the remaining pieces. Serve plain or brushed with melted butter and sprinkled with herbs!
TIPS: For the most bubbles, don't roll out the ball of dough until just before it is ready to be placed in the skillet. I experimented with different skillet temperatures and found that a medium heat produces the most bubbles in the dough and does not burn the surface.