Stir the yeast in the water and set aside for 5 minutes, or until it starts to bubble up.

Mix flour, salt, and sugar in a large bowl.

Gradually pour the yeast water and oil into the dry ingredients. Stir well to bind, then knead for 5 to 10 minutes. The dough should be smooth and elastic, and feel a bit like an earlobe.

Place the dough into a large bowl greased with olive oil. Place a damp tea towel over the dough and let rise in a warm place for 1 1/2 to 2 hours, or until doubled in size.

Punch down the dough. Divide the dough into four equal-sized pieces.

Place the dough back into the bowl and let rest for an extra 30 minutes.

Preheat oven to 450F.

On a floured surface, roll each ball of dough into a disc about 10-inches or 25-cm in diameter.

Transfer the dough to a cookie sheet.

Mix the za'atar spice mixture and olive oil to make a paste. Spread evenly over the four dough discs.

Bake 20 minutes, or until the crust is baked and golden brown.