Preheat oven to 200°F. Using a pencil, draw a 9-inch circle on a parchment paper sheet. Use a cake pan or a plate to trace the circle. Turn the parchment paper over and place it in a baking sheet. The paper should be turned over so the pencil marks are not exposed to the meringue.

In the bowl of an electric mixer fitted with the whisk attachment, beat egg whites, salt, and cream of tartar together until glossy peaks form. With mixer running, add sugar in three additions, beating until meringue is stiff and glossy. Add cornstarch and almond extract and beat at low speed until just combined. 

Mound the meringue in the center of the 9-inch circle. Using a spatula, evenly spread meringue out towards the edges. Create a little nest by making the sides a litter higher than the center. Place meringue in the oven and bake for 2 hours. Turn off the oven and leave meringue inside for at least 2 hours (you can also leave it in the oven overnight).

When meringue is ready, mix all the ingredients of the fruit topping and set aside for about 15 minutes. In the meantime, prepare the whipped cream. Whip the cream in the bowl of an electric mixer fitted with the whisk attachment, when it start to form soft peaks, slowly add sugar and vanilla. Do not overbeat.

Assemble the pavlova by topping the meringue disk with whipped cream and berries. Berries will release some juices; you can add some of the juice on top. Garnish with mint.