There are several possible ways to go with focaccia, depending on the texture you like. Here’s my base recipe, and I’ll do my best to show you how to vary it.
16 ounces bread or high-gluten flour (substitute durum flour for up to half of it)
16 ounces poolish or starter preferment (directions for both to the right, you’ll need to double the poolish recipe and/or grow the starter as needed)
1/4 teaspoon instant yeast
1 3/4 teaspoons salt
2 ounces olive oil
1 tablespoon honey
9 ounces lukewarm water
toppings of your choice
Combine all the ingredients with 5-6 ounces of the water in the bowl of a mixer fitted with a dough hook (not the toppings though, obviously). Mix on low for one minute to moisten all your ingredients, then turn the machine up to medium and knead for a full 15 minutes. You want your finished dough to be smooth and silky but still quite wet, so as the mixer is running add more water if it seems too stiff. It should clear the sides of the mixer bowl, but still stick to the bottom…all in all a consistency not unlike melted mozzarella cheese.
Apply cooking spray or olive oil to a bowl or dough rising container and cover with plastic wrap or a lid. Let rise until doubled, about four hours. Turn the dough out onto a well-oiled 18″ x 13″ sheet pan and let it rest for 10 minutes. After the time is up, with oiled fingers, spread/stretch the dough gently outward. If it springs back too much (and it will) allow it to rest for 5-10 minutes before stretching it more. Repeat the stretching and resting one or two more times, until the dough is most of the way to the edges of the sheet pan. Let proof one more hour, or until the dough starts to get puffy again and spreads out nearly to the corners of the sheet pan (alternately, for still better flavor, put the sheet pan in a clean trash bag and let rest overnight in the fridge…remove 2 hours before baking to allow it to warm up and proof).
Preheat your oven to 500 or 550 (whatever your oven will put out). With your fingers, dimple the dough all over so as to prevent the top crust from rising off the bread in one big bubble as it bakes. Apply a drizzle of olive oil, some fancy salt, herbs, or whatever toppings you wish. Bake for five minutes. Drop the heat to 425. Open the oven door, rotate the pan, and bake about another 20-25 or until golden. Cool on a wire rack and serve.