Meanwhile, get ready your onions: Heat a big sauté pan in excess of medium heat. After warm, insert 2 tablespoons olive oil. After the oil is heated, include the onions and 1 teaspoon kosher salt. Cook onions, stirring every moment or two, till a medium brown, almost caramel coloured, about 25 minutes. [See Note at end.] Scrape onions onto a plate to great whilst you end 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 major of the dough with a different tablespoon of olive oil and use your fingers to dimple the dough, flattening it out. It is ok if it does not reach the edges. Enable the dimpled dough relaxation at home temperature for 15 minutes and warmth your oven to 425°F. Immediately after 15 minutes, dimple the dough only in which wanted a little further into the corners. Enable rest for a last 15 minutes before scattering the leading with onions, poppy seeds, and a several pinches of salt.
Bake the focaccia: For 25 minutes, till deeply golden brown at the edges and throughout the best. Whilst it bakes, you can put together any toppings you’d like to provide it with, these as cream cheese or butter, lox, thinly sliced tomatoes, cucumbers, onions, or capers.
To serve: Loosen the focaccia if it is caught in any spot and slide it into a chopping board. Slice into 12 squares, making use of a sharp knife to get as a result of the onions on leading without the need of pulling them off, and replacing any that scatter. Try to eat right absent.
Do ahead: Focaccia keeps at room temperature for 1 to 2 days. Reheat on a baking sheet at 350°F for 10 to 12 minutes.
Be aware: These are not caramelized onions we do not need to have 60 to 90 minutes in excess of reduced heat with frequent stirring. That is not how any ancestor of mine cooked onions. I’m deliberately utilizing a increased heat for extra swiftly produced flavor. If they are not selecting up colour by 20 minutes, bump up the warmth somewhat. If they’re coloring much too quickly to make it to 20 to 25 minutes, cut down the heat. We want to stopping shy of a darkish bronzed shade, as the onions will end in the oven and we really don’t want them to burn up.