Ok here goes - again this is the recipe from the Muff Kitchen on Instagram and her baking school is worth EVERY PENNY so you should all go sign up - she has this recipe (and many others) with videos and photos so you know what to do.
The night before, make your levain with 15g starter, 50g strong white and 50ml water.
The next morning, mix together 500g strong white and 425ml water, leave to autolyse for 3 hours.
Squish through the levain and leave another hour.
Squish through 12g sea salt and then for the next 2 hours do a stretch and fold every 30 mins.
At the end of the 2 hours, add 100ml olive oil and continue stretch & fold every 30 mins for another 2 hours (the dough kind of swims in the oil, just keep going and don't worry if it doesn't incorporate).
Scoop into a baking tray lined with baking paper or very very oiled. Cover and leave to prove for 2 hours to get super bubbly (I helped it stretch out a few times as well by pulling it from underneath). Fridge overnight uncovered.
Next day, preheat oven to 220c. Prod the foccacia with your fingers going right through to the bottom of the tray to make dimples all over, and pour over another 50-100ml of olive oil. If you want to put toppings on, now's the time.
Bake at 220c for 30 mins - mine is a fan oven and could probably have come out after 25 mins to be a bit paler.