In the meantime, prepare your onions: Warmth a huge sauté pan in excess of medium warmth. When incredibly hot, add 2 tablespoons olive oil. At the time the oil is heated, include the onions and 1 teaspoon kosher salt. Prepare dinner onions, stirring each moment or two, right up until a medium brown, almost caramel coloured, about 25 minutes. [See Note at end.] Scrape onions on to a plate to amazing when you complete the bread.
End the focaccia: When the dough is doubled, line a 9×13 cake pan with parchment paper and drizzle 2 tablespoons olive oil around it. Do not deflate your dough, just scrape it on to the oiled parchment. 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 okay if it does not reach the edges. Allow the dimpled dough relaxation at place temperature for 15 minutes and heat your oven to 425°F. Following 15 minutes, dimple the dough only wherever required a minimal further more into the corners. Allow rest for a ultimate 15 minutes right before scattering the best with onions, poppy seeds, and a few pinches of salt.
Bake the focaccia: For 25 minutes, until deeply golden brown at the edges and throughout the best. While it bakes, you can prepare any toppings you’d like to provide it with, such as cream cheese or butter, lox, thinly sliced tomatoes, cucumbers, onions, or capers.
To provide: Loosen the focaccia if it’s caught in any area and slide it into a chopping board. Slice into 12 squares, applying a sharp knife to get by the onions on leading devoid of pulling them off, and replacing any that scatter. Consume suitable away.
Do ahead: Focaccia keeps at home temperature for 1 to 2 days. Reheat on a baking sheet at 350°F for 10 to 12 minutes.
Observe: These are not caramelized onions we do not require 60 to 90 minutes above very low warmth with frequent stirring. That is not how any ancestor of mine cooked onions. I’m deliberately employing a larger warmth for additional immediately made flavor. If they’re not finding up colour by 20 minutes, bump up the warmth somewhat. If they are coloring also quickly to make it to 20 to 25 minutes, minimize the warmth. We want to stopping shy of a dark bronzed color, as the onions will complete in the oven and we don’t want them to burn.