Meanwhile, put together your onions: Heat a big sauté pan more than medium heat. At the time sizzling, increase 2 tablespoons olive oil. The moment the oil is heated, insert the onions and 1 teaspoon kosher salt. Prepare dinner onions, stirring just about every minute or two, right up until a medium brown, practically caramel colored, about 25 minutes. [See Note at end.] Scrape onions onto a plate to amazing though you finish 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 all right if it doesn’t arrive at the edges. Enable the dimpled dough rest at area temperature for 15 minutes and heat your oven to 425°F. Right after 15 minutes, dimple the dough only wherever needed a tiny even more into the corners. Allow relaxation for a closing 15 minutes right before scattering the prime with onions, poppy seeds, and a handful of pinches of salt.
Bake the focaccia: For 25 minutes, till deeply golden brown at the edges and across the best. Although it bakes, you can get ready any toppings you’d like to provide it with, these kinds of as cream cheese or butter, lox, thinly sliced tomatoes, cucumbers, onions, or capers.
To provide: Loosen the focaccia if it is stuck in any place and slide it into a chopping board. Slice into 12 squares, working with a sharp knife to get by way of the onions on major without having pulling them off, and replacing any that scatter. Take in suitable away.
Do ahead: Focaccia retains at room temperature for 1 to 2 days. Reheat on a baking sheet at 350°F for 10 to 12 minutes.
Take note: These are not caramelized onions we do not want 60 to 90 minutes about minimal warmth with consistent stirring. That is not how any ancestor of mine cooked onions. I’m deliberately using a larger heat for far more immediately formulated flavor. If they are not choosing up coloration by 20 minutes, bump up the heat a little. If they’re coloring far too rapid to make it to 20 to 25 minutes, lessen the heat. We want to stopping shy of a dim bronzed colour, as the onions will end in the oven and we do not want them to burn off.