I love how this bread can be made in just an afternoon and doesn't require any special fancy bread flour, so I almost always have all the necessary ingredients in my pantry. This is taken from Anne Burrell's excellent recipe
Combine the warm water, sugar, and yeast in a bowl and place in a warm place for 15 minutes to bloom the yeast
Set up your stand mixer with the dough hook and add the flour and 1 tablespoon of kosher salt along with 1/2 cup of olive oil and the yeast mixture, then knead on low speed until a dough comes together
Once the dough has formed, increase to medium speed and knead for 5-6 minutes
Transfer dough to a clean lightly floured surface and knead by hand for a minute
Coat your mixer bowl or another metal bowl with a thin layer of olive oil, place the ball of dough in the bowl, and cover with plastic wrap. Set in a warm place for an hour to rise
The dough should have doubled in size after being left to rise
Add the other 1/2 cup of olive oil to a jelly roll pan (half sheet pan)
Add the dough to the pan and press it out with your hands to stretch the dough to fit the shape of the pan. Flip the dough at least once to make sure its all well coated with oil. It will feel like there's way too much oil but don't worry, this is totally on purpose and the bread will turn out great in the end. The oil is what makes it so tasty
Once the dough is spread out to the appropriate size, use your fingers to poke holes in the dough, which will help to create the unique look of focaccia
Allow the dough to rise in the pan for another hour in a warm place. This is a good time to preheat your oven to 425 degrees Fahrenheit (218 C)
Right before the dough goes into the oven, sprinkle the top with some nice flaky sea salt (Malton salt is a good one) or kosher salt, and if you'd like to add some fresh herbs like rosemary, now would be a good time to do that
Bake for 25-30 minutes, until the top is nicely browned, then remove and allow to cool before serving