Preheat the oven to 200°F (93°C) and line a baking sheet with parchment paper.

In a clean mixing bowl, combine egg whites and cream of tartar. Whip on medium speed until frothy and soft peaks form (2-3 minutes).

Gradually add sugar, one tablespoon at a time, while whipping on medium-high speed until stiff, glossy peaks form (5-7 minutes).

Gently fold in green gel food coloring until evenly combined, keeping the mixture airy.

Pipe three dollops of meringue in decreasing sizes to create a tree shape, then add sprinkles on top.

Bake in the preheated oven for 45-50 minutes until dry to the touch and easy to peel off parchment.

Turn off the oven and cool the meringues inside for at least 1 hour or overnight.

Carefully remove from parchment and serve on a festive platter.