pistachio parsley pesto

1. In a small saucepan, bring vinegar and raisins to a simmer and cook until plumed and soft, 3- 5 minutes. Set aside to cool in liquid.

2. When cool, drain raisins (discard liquid) and combine with pistachios, garlic, parsley, chile flakes and olive oil in a small mixing bowl. Season to taste with salt and black pepper and stir until well mixed. Cover the surface with plastic wrap and refrigerate until ready to use.

stuffed focaccia

1. Mix flour and all but a tablespoon of water in a large bowl until just combined, then cover and set aside for 20 minutes to rest. Sprinkle yeast over remaining warm water and set aside to dissolve. 
2. Sprinkle salt over the surface of the dough. Stir yeast mixture and pour over dough.  Lightly wet your hand, reach under the dough, and pull about a fourth of it over the top. Repeat until the center of the dough is enclosed. Then, using your thumb and forefinger as pincers, squeeze and pinch off big chunks of dough. It’s okay to wet your hand a few times to prevent sticking. Pinch through the dough five to six times, rotating the bowl as needed, then fold the dough over itself a few times. Repeat pinching and folding until the yeast and salt are fully incorporated. Cover the bowl and lest rest about an hour. 
3. Fold the dough one time to develop the gluten. Lightly wet your hand, reach underneath the dough and pull about a quarter of the dough up just until you feel resistance, then fold it over the top. Rotate the bowl and repeat this folding four to five times, or until the dough has tightened into a ball. Take the entire ball of dough and invert it into a clean, lightly greased bowl, so the seams are now face down and the top is smooth. Cover and let rise until doubled in volume, 5- 6 hours.
4. Turn the dough out onto a lightly floured work surface and cut in half. Gently shape each half into a ball (see note below) and transfer to a greased plate. Lightly oil the tops, cover and let rest for about an hour. Alternatively, cover tightly with plastic wrap and refrigerate for up to 2 days.
5. Preheat the oven to 425°F.
6. Lightly oil a baking sheet and set aside. Transfer a dough ball to a lightly floured surface and press into a rectangle shape. Carefully pick up and stretch dough into a freeform rectangle, roughly 9-inches by 13 inches. Try to get the dough as thin as you can without tearing it. Carefully place the sheet of dough on the prepared pan. Spread parsley pistachio pesto evenly over the surface of the dough (you may not need all of it), leaving about a 1-inch perimeter empty. Scatter mozzarella on top of the pesto, then brush the empty edge with egg wash.
7. Stretch and pull the remaining ball of dough into a matching rectangular shape and carefully drape it on top of the stuffed focaccia layer. Gently press on the top layer of dough to smooth the surface and remove air pockets. Line up edges and firmly press together to seal. Drizzle top with olive oil and sprinkle with flaky salt. Use a sharp knife to cut a few slits in the top for steam to escape (I find that jiggling the tip of the knife in the dough helps make a hole that stays open).
8. Bake for 20- 25 minutes, or until focaccia is golden and crispy on top and firm to the touch. Let cool slightly, then cut into strips to serve. If desired, serve with olive oil and balsamic vinegar for dipping.