Place the flour and salt into the Thermomix bowl and blend 5 sec/speed 5.
Add yeast and water and knead 4 min/Interval.
Pour the EVOO into a large bowl and tip the dough out on top. Using a silicone spatula, turn the dough by folding in from the edges, bringing some of the EVOO into the dough as you fold.
Cover with cling film and allow to rest for 30 minutes. Repeat this process at least 4 times. The oil will incorporate into the dough, but not fully. This is OK.
After the final fold, move the bowl to the fridge for at least 10 minutes.
Preheat the oven to 220°C or hotter and lightly oil a deep 30cm x 20cm baking tray. I used cast iron to get the high temperature.
Push the dough into the tray and massage the oil into the surface of the dough, dimpling it with your fingers.
Top with a few salt flakes, the herbs, potato and onion slices, pushing them into the dough slightly. Drizzle the whole thing with more oil and leave uncovered to rise for another 30 minutes. Before placing into the oven sprinkle generously with more salt flakes.
Bake 20 minutes and then add a grill function to your oven at 250°. Toast the top for around 4-5 minutes, keep an eye on it, you want it to be crunchy and golden. Serve hot.