Preheat oven to 200°F. Line a baking sheet with parchment paper and set aside.
In a large mixing bowl, use an electric hand mixer or stand mixer fitted with a whisk attachment to beat the egg whites and cream of tartar on medium speed until it becomes frothy like cappuccino foam.
Sprinkle in one spoonful of sugar at a time, mixing well in between each addition, until you've added all the sugar. Continue mixing until it becomes stiff peaks.
Add in a few drops of green gel food colouring and mix again until combined.
Transfer the meringue to a piping bag fitted with a large star tip.
Pipe 3 dollops of meringue on top of each other, with the largest dollop on the bottom and getting smaller at the top. Add sprinkles on top of each meringue.
Bake for 45-50 minutes or until the sides of the meringues are dry and the bottoms peel cleanly off the parchment paper. Turn off the oven and leave the meringues inside to cool overnight or crack the door of the oven open and let cool for about 1 hour. Let cool completely before storing.