In a large bowl, combine the warm water, sugar, and yeast. Stir lightly and leave for 10 minutes until frothy. This activates the yeast and ensures the dough will rise properly.

Add the flour and fine sea salt to the yeast mixture, then pour in the olive oil. Mix with your hand or a wooden spoon until a sticky dough forms. The dough should feel soft but not wet.

Transfer the dough onto a lightly floured surface and knead for about 10 minutes until smooth and elastic. Alternatively, use a mixer with a dough hook for 6–7 minutes. When pressed with a finger, the dough should spring back slightly.

Lightly oil a clean bowl, place the dough inside, and cover with a damp cloth. Leave to rise in a warm place for about 1 hour, or until doubled in size. Avoid draughty areas to maintain even rising.

Grease a 20 x 30 cm baking tin with olive oil. Once the dough has risen, gently deflate it with your hands and stretch it to fit the tin. Press evenly to create a uniform thickness.

With your fingertips, press deep indentations all over the dough surface. These dimples will hold pools of oil and herbs, which help flavour and texture the crust.

Cover the tin with a cloth and leave to rise again for about 30 minutes. This second rise ensures a soft and airy crumb while maintaining the bread’s structure.

Preheat the oven to 220°C (200°C fan). Drizzle the top of the dough generously with olive oil, sprinkle with rosemary, and finish with a pinch of flaky sea salt. Press lightly so the herbs cling to the surface.

Bake for 20–25 minutes until golden brown and slightly crisp on top. The base should sound hollow when tapped, indicating it is baked through.

Remove from the oven and drizzle with a final touch of olive oil. Slice into squares or strips and serve warm. Focaccia pairs beautifully with soups, cheeses, or simply dipped in balsamic vinegar.