Preheat the oven to 200ºF (93ºC). Line two baking sheets with parchment paper.
To make the meringues, put the egg whites in the clean, dry bowl of a stand mixer fitted with the whip attachment.
Heat the water and sugar in a small saucepan fitted with a candy thermometer. As the temperature of the syrup climbs close to 240ºF/115ºC, begin whipping the egg whites on medium-high speed, adding the cream of tartar, if using.
When the syrup reaches 240ºF (115ºC), remove from heat and in a slow, steady stream, pour the syrup into the egg whites, making sure you’re pouring it between the whip and the side of the bowl. Pouring the syrup on the whip will cause it to fling and stick to the sides of the bowl, not go into the whites.
Continue whipping the meringue on medium-high speed until smooth and glossy, 5 to 10 minutes. If you lift the whip and they look grainy, continue whipping them.
Using a pastry bag fitted with a star tip, pipe the meringue into shapes on the prepared baking sheets. You can use a plain tip to pipe another shape, or even make the meringues into “nests” using a soupspoon, shaping them like a mound of mashed potatoes with a crater ready to hold gravy in the middle.
Bake in the oven for 1 1/2 to 2 hours, until they feel close to dry when you touch them. Turn the oven off and let the meringues rest in the oven until cool and dry.
To assemble the dessert, arrange the fruits and berries in shallow soup bowls. Place scoops of the strawberry frozen yogurt nestled amongst the fruits and berries, and garnish with herbs.
If you wish to make a strawberry sauce, puree 1 pound (450g) hulled strawberries with 2 tablespoons of sugar and 1 teaspoon lemon juice. Press through a strainer to remove the seeds, and taste, adding more sugar if desired.