In a large mixing bowl, combine the flour and 2 teaspoons of salt.
In a separate smaller bowl, dissolve the yeast and sugar in the warm water. Allow it to sit for about 5 minutes, or until it becomes frothy.
Pour the yeast mixture and ¼ cup of olive oil into the flour mixture. Stir with a wooden spoon until a dough forms.
Knead the Dough:
Transfer the dough onto a floured surface and knead for approximately 10 minutes, or until it becomes smooth and elastic.
Place the dough in a greased bowl, turning it to coat all sides. Cover with a damp cloth and let it rise in a warm area for about 1 hour, or until it doubles in size.
Shape and Second Rise:
Deflate the risen dough gently and move it to an oiled baking sheet. Stretch the dough out evenly to cover the sheet.
Cover again with a damp cloth and allow it to rise for an additional 20 minutes.
Preheat and Garnish:
Preheat your oven to 400°F (200°C).
Use your fingers to create dimples across the surface of the dough. Drizzle it with more olive oil, then generously sprinkle with chopped rosemary and coarse sea salt. Add sliced cherry tomatoes and sliced onion to make a fun design if you want!
Bake:
Place the dough in the preheated oven and bake for 20-25 minutes, or until the top turns golden brown.
Remove from the oven and let it cool slightly on a wire rack before serving.
Notes
Room Temperature: Store leftover focaccia in an airtight container for up to 2 days.
Freezing: Wrap slices in plastic wrap and place in a freezer-safe bag. Freeze for up to 1 month. Reheat in the oven at 350°F (175°C) for a few minutes to restore crispness.