Combine your flours in the bowl of your stand mixer.
To separate sides of the mixing bowl, add your yeast and salt. Try not to let them touch.
Use a paddle attachment on your mixer to combine these dry ingredients.
Still using the paddle attachment on low-medium speed, slowly pour in your water, sourdough discard, and 2 tablespoons of olive oil.
Mix until the ingredients are barely combined to form a very shaggy dough. You just want to make sure there's no flour or other ingredients left on the bottom of the bowl.
When your dough gets to this point switch to the bread hook attachment on your stand mixer.
Mix on low-medium speed for 5 minutes. I use speed 4. Your dough should be very sticky and smooth, almost runny.
Transfer to a large, well-oiled bowl using oiled hands or a dough scraper.
Cover loosely with plastic wrap and leave out at room temperature for about one hour or until doubled in size.
Use 1 Tablespoon of olive oil to grease the pan you intend to use for baking. Be sure you get all the way up the sides.
With oiled hands and a bench scraper tip your dough out of the bowl and into your pan.
Even out the dough a little so that there is equal space on each side. Don't worry if your dough doesn't touch the edges of your pan. It will after it rises a second time!
Lightly cover your dough with greased plastic wrap and leave at room temperature for one hour or until dough has doubled in size again.
Once this stage is complete, place your covered dough in the refrigerator for at least 8 hours, preferably overnight. The longer you leave your dough in the fridge the more sourdough flavor you will taste.
When you are ready to bake your focaccia preheat the oven at 425 F for 20 minutes.
While the oven is heating pour 2 tablespoons of olive oil on top of your dough and use your fingers to poke the dough to create dimples.
Next, sprinkle your herbs on top of the dough and use your fingers to press the herbs into the dough/dimples.
Bake at 425 F for 10-13 minutes if using a sheet pan 12-15 minutes if using a 9x13 15-20 minutes if using 9x9 Or until golden brown and a toothpick comes out clean.