In the bowl of a stand mixer, add 1/2 cup of the water, the yeast, and sugar. Allow to sit at room temperature until foamy, about 5-10 minutes.

Add the remainder of the water, 1/4 cup of the olive oil, the salt, and 1 cup of the flour and beat on medium-low speed for approximately two minutes (use the paddle attachment).

Add the onion.

Switch to the dough hook and beat in the remaining flour in small 1/2 to 1/4 cup portions, until a shaggy dough begins to form. It should just pull away from the sides of the bowl.

On low speed, knead the dough in the mixer until only slightly sticky, about 5-6 minutes.

Cover the dough loosely and let it rest for 20-30 minutes.

Line a heavy rimmed baking sheet with parchment paper and brush the paper with oil.

Place the dough on the baking sheet and using your fingers, gently flatten the dough into an approximately 1 inch thick shape of your choice.

Cover loosely with oiled plastic wrap and let rise until the dough doubles and is around two inches thick.

Make deep indentations with your fingertips over the surface of the dough.

Drizzle the dough with the remaining olive oil and sprinkle with coarse salt.

Place a baking stone on the bottom oven rack and preheat to 425 degrees.

Place the pan with dough on the stone and bake until the bread is lightly browned, 20-25 minutes.

The bread can be served immediately, or at room temperature.