Start the biga 48 hours before you want to eat the pizza. Place the yeast in the water, give it a gentle stir and leave to a minute or two.
Add the flour and mix by hand until incorporated. Stretch and fold the dough several times then place in a 6 litre container with a lid and leave to sit at room temperatures for 12 hours. The biga should be visibly gassy and triple in size.
After the 12 hours has passed, you can make the dough. Mix the flour, water and salt until everything is incorporated and then add the biga. Work the two doughs together on a clean surfact making sure they are completely combined. Cover with a cloth and leave to rest for 20 minutes.
Knead the dough briefly for 30 seconds before transferring to an oiled 6 litre container, cover with a lid and leave at room temperature for 45 minutes.
After the 45 minutes is up, shape the dough into a ball and split the dough in half. Lightly dust with flour then set the two pieces on a floured tray. Cover with cling film or a towel and leave to prove at room temperature for 2 hours.
After the 2 hours has passed pop the tray of dough into the fridge for around 32 hours.
Melt the beef dripping gently in a pan then brush and 8″ x 10″ Detroit style pan liberally with the dripping making sure you cover the base and the sides. Keep warm.
Add one of the dough balls to the pan and stretch it to the corners so it fits the pan to the edges. Push the oysters into the dough laying them in three rows of three evenly spaced.
Cover with cling film and leave to prove for a final 90 minutes. When the dough has doubled in size, add the bone marrow to the remaining beef dripping and pour half of the mixture over the dough and the oysters.
Set Roccbox to around 300 degrees with a low flame and bake the pizza in the front half of the oven 4-5 minutes. Rotate and repeat on the other half for another 4-5 minutes.
Stir the parsley into the remaining beef dripping mixture and pour over the pizza. Leave to rest for a few minutes in the pan before carefully taking the pizza out the tray and cutting into portions (if you’re nice enough to share it!).