Ingredients

• 6 ounces (170 g) liquid sourdough starter (3/4 cup flat, 1 1/2 cups or more bubbly)
• 1 teaspoon instant, rapid rise yeast (or 1 tablespoon fresh yeast) (you can omit this if your starter is very active)*
• 1 cup (120 g / 4 ¼ ounces) whole wheat flour (or more AP flour)
• 1 ¾ cups (225 g / 8 ounces) bread flour
• 1 ¼ cups (285 ml) water, lukewarm
• 2 teaspoons fine sea or kosher salt
• ¼ cup (55 ml) extra-virgin olive oil
• ¼ teaspoon or so crunchy salt, such as Malden or fleur de sel
• optional toppings: ½ cup halved pitted black olives, chopped thyme, rosemary, whole roasted garlic cloves, cherry tomatoes anything else you can think of

Instructions

Combine the starter, instant yeast, water and flours in the bowl of a stand mixer fitted with the paddle or dough hook attachment (both work!). Mix on low a couple of minutes until combined, scrape down the sides of the bowl, then increase to speed 3 and beat for 8 minutes. The dough should be very wet and sticky, almost batter-like, but not liquid. Add more flour or water as you knead if the dough seems overly wet or dry. Sprinkle on the salt, and beat on 3 for another five minutes. The dough should still be sticky, but should pull away from the sides of the bowl while it's mixing.

Leave the dough in the bowl, cover tightly with a lid or plastic wrap, and let rise 1-2 hours until doubled or tripled in bulk.

Line a 9x12" (1/4 sheet) pan with a sling of parchment paper (the paper should lay flat in the bottom with the long ends sticking out.) Spritz 2 tablespoons of the olive oil all over the bottom and sides of the paper.

Pour the dough onto the oiled parchment. Spritz oil on top and use your fingers to dimple the dough outwards towards the sides and corners.

Let the dough rise until doubled in bulk, about 1 hour, until it mostly fills in the pan.

Preheat the oven to 500º, with a tray or baking stone on a lower rack.

Spritz more oil ensuring the top is "basted". Sprinkle a bit of crunchy salt over the top, and any other toppings you like, and give the dough a last dimpling.

After 15 minutes, rotate the focaccia, then turn the oven down to 450º and bake for another 10 minutes, until golden. Remove to a cooling rack for 10 minutes, then lift out of the pan.

Adapted from https://bojongourmet.com/quick-and-dirty-sourdough-focaccia/