Combine the all-purpose and bread flour in a clean bowl. Take 100 grams of the mixed flour and combine it with 60 grams (out of the total 300 grams) and all of the yeast into a large glass or metal mixing bowl. Knead this all together with your hands until well combined, then form a ball cut and set this at the bottom of the bowl. Cut a large X into the dough ball.
Cover with cling wrap, and set the bowl inside the oven at 78°F for 1.5 to 2 hours. After the resting time, the dough should have doubled in size!
Take the bowl out of the oven, remove the cling wrap, then add the rest of the flour, water, and honey. You can either use a mixer for a quicker result or you can knead it by hand. Only knead the dough until everything is combined enough, don’t overdo it too much since the dough should be a little sticky.
Now, add the oil to the dough little by little and start pulling and stringing the dough to combine the oil. Keep stringing the dough until the oil absorbs – it should not feel oily or sticky to the touch but rather elastic and smooth.
Add the salt and mix it in well, then form the dough into a ball and set it on the bottom of the bowl.
Cover with cling film and set it in the oven at 78°F and let it rise for 3 hours. The dough needs to triple in size basically. The timing may vary depending on season/altitude so just keep an eye on it.
Once the dough is ready, take it out and remove the cling wrap. Lightly dust a flat surface with flour (don’t overdo it!) and form the dough into a ball once again, then let it rest on the surface for about 10 minutes.
Lightly dust a rolling pin with flour and roll out the dough. Try to keep it in more of a square shape and a bit thicker. For size reference, it should not completely fill up a baking sheet and there will be space between the dough and the edges of the pan. Transfer this to a lightly greased baking sheet (I recommend using one with slightly higher raised edges since there may be some spillage when the brine is used).
Cover with plastic wrap and leave it to rise for about 40 minutes or so.
Remove the cling wrap and stretch the edges of the dough to the corners of the pan. Cover with plastic wrap and let rise for 1 hour. The dough should have a swollen look to it by the time it is ready.
Now for the key of Focaccia – the holes! I actually recommend using your knuckles for this portion so there is no chance of the dough ripping. First though, you must sprinkle a little bit of bread flour on the surface of the dough and a little on your hands so no sticking occurs. I like to use my pointer and middle fingers knuckles at the same time and start from one corner of the pan and start going across and keep coming down in lines until the whole sheet is done. There should be a solid inch or so between each hole.
Gently use your hands to check for any possible air bubbles and swellings. The dough should be relatively even across the pan.
Now is the time for the brine! Using a glass jar or jug, combine the water, salt, and oil. Don’t shake it, but rather lightly turn it until the salt has dissolved. Now, carefully pour the brine mixture onto the surface of the dough, making sure each hole is full of brine! NOTE: I know, it looks like a LOT of brine, but fear not, it is the right amount and I promise it will be absorbed in the end! Now, set your pan of dough in the oven at room temperature for 1 hour. By that time, at least half of the brine should be absorbed. Take it out of the oven, drizzle a bit of olive oil and sprinkle some salt on top. NOTE: if you would like to add other things to your Focaccia, like olives, sun dried tomatoes, etc, now is the time! Nestle them gently into the brine filled holes and you’re good to go!
Preheat the oven to 480°F and put the pan on the lower rack. Cook for 12 minutes. I recommend checking the bottom of the bread, and if it is slightly golden brown then you are good to move on to the next step!
Transfer the pan to the top rack and let it cook for about 10 minutes or until it becomes lightly golden on top. Remove from the oven, drizzle a bit of olive oil, sprinkle some coarse salt and any herbs you would like on top. Let it cool for a few minutes before you dig in!