After 30 minutes the ball will have grown in size. This is the 2nd rise of the dough. On a lightly floured surface, flatten out the dough using all your fingers, leaving little divots in the dough. Continue this with your palms, remembering to leave an untouched 'rim' of the dough to form that great risen crust.
To get the dough to the correct size to fit your 'skillet' there are many methods to stretching the dough, my favourite is to stretch the dough using the 'slap technique. Do not ever roll your pizza dough with a rolling pin.
If your skillet has quite a shallow lip, you can finish the assembly of the pizza on a pizza peel, otherwise you need to have everything ready and transfer the dough directly to to skillet and top it off there.
Whichever method you use, take a large spoonful of tomato sauce and starting at the centre, lightly distribute the tomato sauce in circles up to the thicker border of the crust.
Place your mozzarella pieces on top, then in-between each piece spread a small dollop of 'nduja and some Parmesan.
Place the skillet with the pizza back in the oven. It should be done at the 5-7 minute mark.
Serve with a drizzle of olive oil and top with more Parmesan and a little basil, if so desired.