Pour the chickpea flour into a saucepan, add the salt, and mix. Add the water little by little and mix it with a whisk until the mixture is lump-free.
Thicken the mixture over medium heat for a few minutes, stirring constantly with the whisk. It should form a sort of polenta that comes off the sides of the pot. The mixture must be compact and not liquid!
Transfer the mixture to a cutting board lined with parchment paper.
Spread with a knife to a thickness of 0.25 inches.
Let it cool at room temperature for about 20 minutes.
Lay a second sheet of parchment paper on the surface and roll out with a rolling pin without squeezing, but just to create a uniform surface.
Shape the edges so as not to waste dough and let it cool completely before cutting your squares. Use a square or rectangular cookie cutter. Circles are also good, or you can simply use a knife.
Fry in plenty of oil in a large pan for about 2 minutes without turning.
Drain on absorbent paper, sprinkle with salt, and if you prefer, squeeze a few drops of lemon juice over it.
Notes
If you prefer a less oily variation, you can bake panelle in the oven at 400°F on parchment paper for about 15 minutes, then turn on the broiler for the last few minutes.