1. 1. Activate the Yeast and Discard: In a large mixing bowl, combine the warm water, sourdough discard, 2 tablespoons of olive oil, active dry yeast, and granulated sugar. Whisk gently until the yeast and sugar are mostly dissolved and the discard is well incorporated. The mixture should look a bit cloudy.

2. 2. Combine Dry Ingredients: Add the all-purpose flour and 1 1/2 teaspoons of fine sea salt to the wet mixture. Use a wooden spoon or a spatula to mix until a shaggy dough forms and no dry streaks of flour remain. Do not overmix; a slightly sticky dough is expected.

3. 3. First Rise and Stretch: Cover the bowl with plastic wrap or a damp kitchen towel and let the dough rest in a warm place for 30 minutes. After 30 minutes, perform a series of “stretch and folds”: with wet hands, gently grab one side of the dough, stretch it upwards, and fold it over to the opposite side. Rotate the bowl a quarter turn and repeat this process 3-4 more times. This helps develop gluten without heavy kneading.

4. 4. Second Rise and Pan Prep: Lightly grease a 9×13 inch baking pan with a generous amount of olive oil, ensuring the bottom and sides are well coated. Transfer the dough into the prepared pan. Gently spread the dough to roughly fill the pan. Cover the pan loosely with plastic wrap or a damp towel and let it rise in a warm spot for 1 hour. The dough should look visibly puffy and have increased in volume.

5. 5. Dimple and Top the Dough: Once the dough has risen, uncover it. Drizzle a little more olive oil over the top. Using oiled fingertips, gently press down into the dough to create those characteristic focaccia dimples. Don’t be afraid to press all the way down to the bottom of the pan. If using optional toppings like fresh rosemary or cherry tomatoes, arrange them evenly over the dimpled surface. Sprinkle generously with flaky sea salt.

6. 6. Bake to Golden Perfection: Preheat your oven to 400 F (200 C). Bake the focaccia for 20-25 minutes, or until the top is golden brown and the edges are crisp. The internal temperature should reach around 200-210 F (93-99 C) if you’re using a thermometer.

7. 7. Cool and Serve: Once baked, carefully remove the focaccia from the oven. Let it cool in the pan for a few minutes before transferring it to a wire rack to cool completely. Slicing it while still warm is fine, but allowing it to cool slightly helps set the texture.