In the meantime, get ready your onions: Warmth a huge sauté pan more than medium warmth. The moment hot, include 2 tablespoons olive oil. Once the oil is heated, increase the onions and 1 teaspoon kosher salt. Prepare dinner onions, stirring each moment or two, until finally a medium brown, pretty much caramel coloured, about 25 minutes. [See Note at end.] Scrape onions onto a plate to neat whilst you complete the bread.
Finish the focaccia: When the dough is doubled, pour 2 tablespoons olive oil into a 9×13 cake pan. Do not deflate your dough, just scrape it into the oiled pan. Drizzle the top rated of the dough with one more tablespoon of olive oil and use your fingers to dimple the dough, flattening it out. It’s ok if it doesn’t access the edges. Let the dimpled dough relaxation at home temperature for 15 minutes and warmth your oven to 425°F. Following 15 minutes, dimple the dough only in which needed a minimal additional into the corners. Enable rest for a remaining 15 minutes right before scattering the best with onions, poppy seeds, and a handful of pinches of salt.
Bake the focaccia: For 25 minutes, until eventually deeply golden brown at the edges and throughout the prime. Even though it bakes, you can get ready any toppings you’d like to serve it with, such as product cheese or butter, lox, thinly sliced tomatoes, cucumbers, onions, or capers.
To provide: Loosen the focaccia if it is trapped in any put and slide it into a chopping board. Minimize into 12 squares, using a sharp knife to get through the onions on leading without pulling them off, and changing any that scatter. Consume correct absent.
Do ahead: Focaccia keeps at place temperature for 1 to 2 times. Reheat on a baking sheet at 350°F for 10 to 12 minutes.
Observe: These are not caramelized onions we do not need 60 to 90 minutes above minimal heat with constant stirring. That is not how any ancestor of mine cooked onions. I’m intentionally applying a bigger warmth for additional promptly created taste. If they are not picking up color by 20 minutes, bump up the heat slightly. If they’re coloring as well quickly to make it to 20 to 25 minutes, reduce the warmth. We want to halting shy of a dark bronzed coloration, as the onions will finish in the oven and we really do not want them to burn up.