Put the water, ½ tbsp of the sugar and yeast in a small jug, stir and let sit for 5 minutes, or until foamy.
Mix the flour in a large bowl, make a well in the centre. Pour in the yeast mixture and the olive oil and use your hands to mix the flour together. Knead until you have a smooth springy ball of dough. (Alternatively you could do all this in an electric stand mixer fitted with a dough hook).
Drizzle a little olive oil into a large bowl, place the dough in and turn to coat, cover with cling wrap and place in a warm place for 1 hour, or until dough has doubled in size. Alternatively place in the fridge and allow to rise slowly overnight.
Punch dough down and knead for a couple of minutes on a lightly floured surface.
Preheat oven to 200°C (390°F). Line a large rectangular oven tray with baking paper.
Cut the dough into two equal sized pieces. Roll each piece on a lightly floured surface into a rough rectangular shape until about 1 cm (1/3inch) thick.
Place one half of dough onto the oven tray. Sprinkle half the grapes, half the remaining sugar, half the fennel and half the rosemary onto the dough.
Brush edges with a little egg wash and top with the second piece of dough and cut a few small incisions into the top to allow steam to escape.
Brush all over with beaten egg, pinch the edges together to seal and sprinkle all the remaining ingredients on top, pressing gently with your fingertips so they stick into the dough.
Place in the oven and bake for 35–40 minutes, or until the top is dark golden. Allow to cool slightly before slicing and serving.
