This focaccia with red onion and rosemary has that iconic crunchy, perfectly salted surface and a tender texture beneath. It's topped with caramelized onions and fragrant rosemary and makes a worthy distraction—both the making and the devouring.
In the bowl of a stand mixer fitted with the dough hook, weigh out the flour, 1 2/3 cups water (400 g), salt, yeast, and 1 1/2 tablespoons olive oil.
Mix on slow speed for 4 minutes, then turn the mixer up and mix on high speed for 6 minutes. Let the dough rest in the mixer for 15 minutes.
☞ TESTER TIP: The dough is very wet and sticky, so you’ll definitely want to let your stand mixer do the kneading as it’s quite difficult to do so by hand. (Don’t ask us how those Italian nonnas did it back in the day.)
Restart the mixer on slow, add the remaining water, and mix for 4 minutes more.
Transfer the dough to a container, preferably plastic and with a lid, that’s large enough for the dough to at least double and let rise at warm room temperature, using a spatula to fold the dough (in the container, if you can, without turning it onto a work surface every 15 minutes. Let it rise for about 1 hour, until approximately doubled in size.
Cover the container and refrigerate overnight.
Two hours before baking, tip the dough into a lightly oiled 8-by-12-inch or 9-by-13-inch (20- by 30-cm or 23- by 33-cm) baking or sheet pan, and with wet hands stretch out the dough to fit the pan. Let it rest at room temperature for 2 hours, giving the dough a stretch every 30 minutes or so if it begins to shrink back from the sides of the pan.
Thirty minutes before baking, preheat the oven to 450ºF (230°C).
Sprinkle the top with salt and scatter with the onions and rosemary. Bake until cooked through and golden on the bottom when you lift a corner and peek, 17 to 20 minutes. Drizzle with extra virgin olive oil and serve.