First make the dough. Mix all the dry ingredients together. Mix the wet ingredients together. Add the dry ingredients to the mixer bowl, this dough is much better in the mixer. It’s a very wet dough for the Schiacciata so a mixer is the best way. But if you’re feeling confident, rocking your Richard Bertinet vibes, then knock yourself out.
Anyways…. add the wet ingredients to the mixer, turning it on slowly until the dough comes together. Then knead with the mixer until it becomes smooth. Leave to prove in the bowl until it doubles in size.
Meanwhile, thinly slice the peeled potatoes. Put in a saucepan and cover with water, lightly salt the water. Cover the pot and bring to the boil. Boil for about 5 minutes. Drain all the water off carefully and refresh with cold water. Leave to one side.
Split the risen Schiacciata dough in half. Roll one of the pieces of dough into a lined swiss roll tin. Leave to rest for 30 minutes. Use the other half of the dough to make rolls or paninis.
After the resting time, spread the onion marmalade onto the dough, leaving a 1cm edge free all around the rolled out dough.
Next, drain and dry the slices of potato, then overlay the slices of potato over the onion marmalade. Season well, then drizzle oil all over the finished Schiacciata.
Bake for 35 to 4o minutes until the potato slices look crispy around the edges and the dough is cooked. 5 minutes before the end of cooking you could add the grated cheese to make it a little more filling. Just Divine.