Pour the aquafaba (liquid from the chickpea can) in a mixing bowl, add the cream of tartar and mix with the hand mixer for about 5 minutes.
Add about a quarter of the sugar at a time and continue to mix until the meringue becomes glossy and when removing the hand mixer, sharp peaks form and hold. The meringue is ready.
Pour two third of the mixture in a pipe bag (or ziploc bag) and open the tip.
Line a baking tray with parchment paper.
Point the pipe bag vertically and gently pour a little bit of the meringue to form small disks. These will be the mushroom caps.
Then use the mixture to form small sticks, these will be the mushroom stems. Keep in mind we will need more stems than caps. Reserve some of the white meringue to decorate the red mushroom caps.
For the remaining third of the meringue, add the red food coloring and mix it with the hand mixer for a minute or so until the meringue becomes red. Then pour the red meringue in a pipe bag and repeat the same process to obtain the mushroom caps only.
Use a chopstick or anything with a thick point to decorate the red mushrooms with the RESERVED white meringue. The goal is to create a polka dot pattern on each red mushroom cap.
Place the tray in the oven and bake for 90 minutes.