In a very large bowl, stir together 600g of the water with the yeast and the honey. Let sit for 5 minutes, until frothy.

Use your hands or a large spoon to mix the flour into the yeast mixture until all the flour is incorporated. Cover with a clean, damp tea towel and let sit for 30 minutes.

Add the remaining 120g water, the kosher salt and the oil. Use your hands to incorporate. As the dough absorbs the salt, it will behave sort of strangely, seeming to fall apart – this is fine. Just keep kneading and squeezing it with your hands – it’ll come back together eventually, especially once it has a chance to rest.

Cover the bowl with a damp tea towel and set it in a warm spot to continue proofing. Every 30 minutes or so for the next 2½ hours, turn the dough. (Note that each turn consists of four quarter-turns, or folds.)

After about 3 hours total, the dough should be billowy and have doubled in volume. If not, continue to let rise and turn for up to 1 hour longer.

After the final set of folds, gather up the edges of the dough into the centre and then carefully flip it to tuck the join underneath. Gently coat the top of the dough with a little oil, seal the bowl with cling film or a lid, and refrigerate for 12–24 hours.

Generously coat the bottom and sides of a 33 × 46cm baking tin with nonstick cooking spray, then drizzle with 2–3 tbsp oil. Gently transfer the dough to the tin, cover with cling film or a lid, and set in a warm spot to come to room temperature for 30 minutes.

With lightly oiled hands, gently stretch the dough to fill the tin, then drizzle with another 2–3 tbsp oil. Return the pan to a warm spot and allow to proof for 30 minutes.

Gently stretch the dough again to fill the entire tin. Repeat the stretching twice more over the next hour, then continue proofing the dough untouched until it’s jiggly, bubbly and flush with the top of the pan, 1–2 hours longer.

Meanwhile, adjust an oven rack to the lowest position, place an overturned baking tray on the rack and preheat to 230°C.

Once the dough is flush with the top of the tin, dip the pads of your fingers in any oil that’s pooled in the corners of the tin. Spread your fingers wide and make dimples across the dough, pressing firmly to the bottom of the tin.

Sprinkle evenly with flaky salt.

Place the baking tin with the focaccia on the overturned baking tray in the oven and bake for 25–28 minutes, until the corners are pulling away from the tin and the top is golden brown and glistening.

Cool the focaccia in the tin for 5 minutes, then use a thin flexible metal spatula to gently loosen it from the tin. Cool completely on a wire rack before slicing.

Store for up to 3 days wrapped in a paper bag inside of a plastic bag. Bring back to life with a quick toast. Freeze for up to 3 months.