Preheat the oven to 400˚ F, and line a baking sheet with parchment paper.
Whisk together the flour, salt, cheese and fresh rosemary in a large mixing bowl. Add the water a little at a time, using a fork and your fingers to mix it into the flour mixture, until a ragged dough starts to form.
Empty the mixture out onto a lightly floured workspace, and knead with your hands until the dough comes together into a smooth ball, about 2 - 3 minutes.
Flatten into a disk shape, and roll to about ⅛" thick. Place on the prepared baking sheet.
Sprinkle a little olive oil over the surface, along with a few pinches of salt flakes or coarse sea salt.
Bake for 15 minutes. Turn the baking sheet around and bake for another 5 minutes.
Serve with olive oil on the side.