Preheat the oven to 140°C/fan 120°C/gas 1. Line a baking sheet with parchment paper. Draw large, medium and small heart shapes, measuring 24cm, 20cm and 16cm in length, on the underside of the parchment paper, ensuring that you can see the shape through the paper.
Place the egg whites in a spotlessly clean, dry bowl. With an electric hand mixer, whisk the egg whites until stiff but not dry. Gradually whisk in half of the caster sugar, a tablespoon at a time. Fold in the remaining sugar.
Spoon the meringue mixture into a piping bag with a plain nozzle. Secure the parchment paper to the baking sheet with a little of the meringue mixture to ensure the paper doesn’t lift in the oven. Following the outline of the heart shapes, fill in the shapes.
Bake immediately for 1 1⁄2 hours, or until set. When the meringues are done, leave them in the oven with the oven door slightly open so that the meringues can cool.
Meanwhile, to prepare the raspberries, place the red wine, honey and thyme in a saucepan and warm through. Remove from the heat and pour over the raspberries. Cool and place in the fridge for 30 minutes.
To make the filling, melt the chocolate and butter in a bowl over a pot of simmering water. Allow to cool, then fold in the whipped cream.
To make the sauce, gently remove the raspberries from the liquid with a slotted spoon, taking care not to break them, and set aside. Strain the liquid through a sieve and return it to the saucepan. Add the arrowroot mixture and heat the liquid to thicken it to a light sauce consistency.
Spread the large and medium meringue hearts with some of the chocolate mixture and top with raspberries. Starting with the largest heart at the bottom, pile the meringues on top of each other.
Decorate with chocolate shavings and sprigs of thyme. Drizzle generously with the raspberry thyme sauce.