In the meantime, get ready your onions: Heat a huge sauté pan around medium warmth. At the time sizzling, include 2 tablespoons olive oil. The moment the oil is heated, increase the onions and 1 teaspoon kosher salt. Prepare dinner onions, stirring each minute or two, right until a medium brown, nearly caramel colored, about 25 minutes. [See Note at end.] Scrape onions onto a plate to neat although 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 prime of the dough with an additional tablespoon of olive oil and use your fingers to dimple the dough, flattening it out. It is ok if it doesn’t attain the edges. Allow the dimpled dough relaxation at space temperature for 15 minutes and warmth your oven to 425°F. Soon after 15 minutes, dimple the dough only in which desired a tiny more into the corners. Let relaxation for a closing 15 minutes ahead of scattering the leading with onions, poppy seeds, and a few pinches of salt.
Bake the focaccia: For 25 minutes, until eventually deeply golden brown at the edges and throughout the major. Whilst it bakes, you can get ready any toppings you’d like to serve it with, these as cream cheese or butter, lox, thinly sliced tomatoes, cucumbers, onions, or capers.
To serve: Loosen the focaccia if it’s caught in any place and slide it into a reducing board. Lower into 12 squares, making use of a sharp knife to get by the onions on best without the need of pulling them off, and changing any that scatter. Eat right absent.
Do in advance: Focaccia retains at home temperature for 1 to 2 days. Reheat on a baking sheet at 350°F for 10 to 12 minutes.
Note: These are not caramelized onions we do not need 60 to 90 minutes above minimal warmth with constant stirring. That is not how any ancestor of mine cooked onions. I’m deliberately working with a better heat for extra immediately developed taste. If they are not selecting up color by 20 minutes, bump up the heat a little. If they’re coloring as well rapidly to make it to 20 to 25 minutes, cut down the heat. We want to halting shy of a dim bronzed color, as the onions will end in the oven and we don’t want them to burn off.