Preheat the oven to 250°F (120°C) and line a baking sheet with parchment paper.

In a clean, dry bowl, whip the egg whites until frothy. Add the cream of tartar and continue to whip until soft peaks form.

Gradually add the sugar, one tablespoon at a time, while continuing to whip until the meringue is glossy and stiff peaks form.

Spoon or pipe the meringue into circular shapes on the prepared baking sheet, creating nests with a small indentation in the center.

Bake for 1.5 to 2 hours, until the meringues are dry and crisp. Turn off the oven and let them cool inside.

While cooling, mix the mango puree and miso paste in a bowl until smooth.

Once the meringues are cool, fill the center of each with the mango-miso mixture.

Serve with whipped cream and garnish with mango slices if desired.