Preheat the oven to gas ½, 130 degrees Celsius, and fan 110 degrees Celsius. Whip the egg whites to delicate peaks with an electric whisk. Whisk in the cardamom until stiff peaks form. 1 tablespoon sugar at a time, beating thoroughly between additions, until the meringue is thick, firm, and glossy.
Place a small amount of the meringue mixture in the corners of two baking sheets, then cover with baking paper (this helps keep the paper steady). Spread the mixture out into 4 mounds (2 on each sheet) and 12cm rounds.
To get a marbled look, drizzle ¼ tsp coulis over each meringue and gently swirl it in with a cocktail stick. Bake for 1 hour, or until hard and readily removed from the parchment paper.
Turn off the oven and allow the meringues inside to cool for 1-2 hours. 2 meringues can be saved in an airtight jar for another recipe or frozen.
To make gentle peaks, whisk the cream. To serve, pour two-thirds of the cream on a platter and top with a meringue.
Arrange the orange segments on top of the cream, then top with another meringue. Dollop the remaining cream on top.
Sprinkle the pomegranate seeds and pistachios on top. Garnish with mint (if using). Drizzle the remaining 1 tsp coulis over the top.
Only unadorned meringues should be frozen. To serve, defrost overnight in the refrigerator before reheating in a saucepan over low heat until hot and bubbling, about 15-20 minutes.