Make the grapes

1. Preheat oven to 400-degrees F. Mix everything together on a big baking sheet and roast the grapes for 20-25 minutes or until soft, fragrant and juicy. Allow to cool slightly before serving.

Make the sponge

1. In a large bowl, pour the water and stir in the yeast. Let stand until bubbly and cloudy. Stir in the flour, cover with plastic wrap and let rise for 45 minutes.

Make the focaccia

1. In a small bowl, combine the water and yeast and let sit until bubbly and cloudy. Pour into the large bowl with the sponge and add the olive oil. Stir in one cup of flour and then the sage, salt and sliced olives. Add the remaining flour and mix well – make sure there are no dry, floury lumps. The batter will be wet, sticky and heavy. Do not add more flour – you are not going to be kneading this dough.
2. Lightly oil another large bowl and using a bowl scraper, pour the dough into the oiled bowl. Cover with plastic wrap and allow to rise for an hour or so.
3. Lightly oil an 11″ x 17″ baking sheet. Transfer the dough onto the baking sheet and using oiled hands, press the dough to cover the pan. Let the dough rest for about 10 minutes, then press the dough again – it tends to want to shrink and bounce back – until the pan is completely covered. Cover with a kitchen towel and let rise again for about an hour.
4. Preheat oven to 425-degrees F. Position an oven rack to the center.
5. When dough has risen, gently press fingertips into dough to create indents. Sprinkle the dough with the chopped sage and kosher salt, spritz lightly with olive oil and bake for about 25 minutes. Focaccia should be browned on the top and sound hollow when tapped. Let cool slightly before cutting. Serve with Sweet & Savory Roasted Grapes.