Preheat oven to 190c (375F) and set aside 2 baking trays (see notes).
Combine za'atar (1 tsp) and ground cumin (¼ tsp) in a small bowl and set aside.
In a medium size bowl, combine plain (all purpose) flour (1cup/150g) and salt (¼ tsp), making a well in the centre.
Add olive oil (2 tbsp) and water (¼ cup) to the well, and mix gradually until you have a shaggy dough (if it looks a little dry add more water 1 tsp at a time). Still in the bowl, use your hands to bring this shaggy dough into a rough ball then turn the dough ball out onto a lightly floured surface.
Knead the dough slightly to make it more uniform, about 10-15 strokes is all it should need.
Divide this ball of dough into three even-ish portions.
Working with one portion at a time, roll out the dough as thinly and evenly as you can - about 1-2 mm (1/18") thick. See images in the post above.
Using a sharp pizza cutter, cut dough into your desired shapes (long strips, squares etc) then place the crackers on a baking tray. You don't want them to overlap, but they also won't spread as they cook.
Using a pastry brush, brush the remaining olive oil (1 tbsp) evenly over the surface of the crackers, then sprinkle them evenly with combined za'atar and cumin.
Finally sprinkle with fine salt to taste and bake for 6-10 minutes, or until golden brown. Allow to cool completely on baking tray.