Preheat the oven to 200°F (95°C) and line two baking sheets with parchment. Beat the egg whites and cream of tartar until foamy, then whip to soft peaks. Gradually add the sugar, beating until stiff, glossy, and grit‑free.

Drizzle in the peppermint extract, then dot the surface with a few drops of red gel coloring. Fold gently 2 or 3 times to create red streaks.

Pipe 1.5‑inch rounds onto the prepared sheets, spacing them about 1 inch apart.

Bake for 90 minutes. Turn the oven off, crack the door, and let the cookies cool in the oven for 1 hour. Peel off the parchment and serve.