Line a baking tray with a fresh (it is important that the surface is grease-free) sheet of baking paper.
In a clean stand mixer bowl (no greasy residue), beat chickpea water and cream of tartar on medium high for a couple of minutes, then on high until you get stiff peaks (5ish minutes).
To test if whipped chickpea water is ready, gently turn the bowl upside down. If the mixture does not start sliding down, you can start adding sugar. Otherwise, keep on whipping until the mixture stays in the bowl when inverted.
Start adding sugar very slowly, tablespoon by tablespoon, whipping well after each addition. Continue until all the sugar has been added. By now, the mixture should become beautifully glossy, thick and sticky - no different to an egg-based meringue, really.
Preheat the oven to 100º C.
Spoon meringue mixture into a piping bag.
Hold the bag perpendicular to the tray and squeeze small blobs of the mixture onto the tray and quickly pull away after each blob. Allow some space around each blob or else the drops may stick together.
Bake for about 75 minutes, then turn the oven off but leave the tray with meringue drops inside with the oven's door slightly open for another 45-60 minutes for the meringues to dry out fully. Keep the meringues in an airtight container.
