1. 1. Activate the yeast and combine wet ingredients: In a large mixing bowl, combine the warm water, granulated sugar, and active dry yeast. Stir gently and let it sit for 5-10 minutes until the mixture becomes foamy. This indicates your yeast is active. Then, stir in the sourdough discard until well combined.

2. 2. Mix in the dry ingredients: Add the all-purpose flour and fine sea salt to the wet mixture. Use a wooden spoon or a sturdy spatula to mix until a shaggy dough forms and no dry streaks of flour remain. The dough will be sticky, which is exactly what you want for focaccia. Avoid overmixing.

3. 3. First rise (bulk fermentation): Drizzle 1 tablespoon of olive oil into a clean, large bowl. Transfer the dough to this bowl, turning it once to coat it lightly in the oil. Cover the bowl tightly with plastic wrap or a damp kitchen towel. Let the dough rise in a warm spot for 1 to 2 hours, or until it has visibly increased in size and looks bubbly. The exact time will depend on the warmth of your kitchen.

4. 4. Prepare the baking pan and dimple the dough: Drizzle 2-3 tablespoons of olive oil generously into a 9×13-inch baking pan. Gently transfer the risen dough into the oiled pan. Use your oiled fingertips to gently stretch and dimple the dough, pushing it to the edges of the pan. Don’t worry if it springs back a bit; it will relax. Create those characteristic focaccia dimples all over the surface.

5. 5. Second rise and preheat oven: Once the dough is dimpled, cover the pan loosely with plastic wrap or a clean kitchen towel. Let it rest for another 20-30 minutes while you preheat your oven to 400 F (200 C). This short second rise helps the focaccia become extra airy.

6. 6. Add toppings and bake: Before baking, drizzle a little more olive oil over the top of the dough. Sprinkle with flaky sea salt and any other desired toppings like fresh rosemary or cherry tomatoes. Bake for 20-25 minutes, or until the focaccia is golden brown on top and cooked through. The crust should be crisp and the interior soft.

7. 7. Cool and serve: Once baked, remove the focaccia from the oven and carefully transfer it to a wire rack to cool slightly. This prevents the bottom from becoming soggy. Slice into squares or strips and serve warm.