Add in the flour, sugar, salt, and chocolate chips. Using your hands or a wooden spoon, mix it all together until well combined. The dough will be fairly dry and crumbly.
Dump the dough onto the lined cookie sheet. Press it into a thin layer using your hands. It may not completely fill the cookie tray. The thinner you press it, the crispier it will be and the quicker it will cook, so adjust accordingly.
Bake for 20 minutes. Check if edges are lightly brown and center is set, then remove from oven.
Allow to cool completely. (This is probably the hardest part; you can put the whole tray in the fridge to speed up the process.)