Sieve flour into a bowl and dig a hollow in the middle of it.
Take 230ml warm water and stir in 1 tbsp agave syrup. Pour the sweetened warm water into the hollow and stir in the dry yeast. Also stir in a bit of flour and cover the yeast for 10 minutes until it will form bubbles. Then stir in all the flour thoroughly, gradually adding the olive oil. Finely chop a few rosemary needles and mix in.
Mix the dough with a pinch of salt and knead vigorously for 3-4 minutes on a lightly floured work surface until smooth. If necessary, powder the worktop with some more flour again.
Spread a bowl with some olive oil and add the dough. Cover the dough and leave to rise in a warm place without draughts for 45-60 minutes until it has approximately triples in size.
Brush a baking tin with a little olive oil and fit in the dough. Cover the dough again and let it rise for another 15-20 minutes. This makes the focaccia particularly fluffy. Preheat the oven to 200 °C/392 °F fan.
Press holes in the dough using your fingers and add the grapes and rosemary needles. I also add another small tbsp. of olive oil here. Cover the focaccia with 2 sprigs of rosemary (and remove them after baking).
Bake the focaccia at 200 °C/392°F fan/circulating air for about 20 minutes until the focaccia is nicely golden. Remove the two rosemary branches.
Enjoy your focaccia sprinkled with olive oil, sea salt and rosemary.