Once the mixture is hot but not boiling, stir in the cornstarch slurry. Bring it to a gentle simmer, stirring constantly, and cook for 1 minute until it thickens slightly.

Remove the pan from the heat and let the mixture infuse with the vanilla pod at room temperature. Once it has cooled slightly, cover with plastic wrap pressed directly onto the surface (to prevent a skin from forming) and chill completely in the fridge.

Arrange the cleaned, whole strawberries on a baking tray lined with parchment paper. Sprinkle with sugar and vanilla sugar, and drizzle with good-quality balsamic vinegar. Toss gently to combine.

Roast the strawberries in a preheated oven at 200°C for about 30 minutes. They should caramelize beautifully, release their juices, and take on a jammy consistency.

Let the roasted strawberries cool completely. Then blend them, juices and all, briefly with an immersion blender or in a small food processor.

Tear fresh basil leaves into a blender. Add cane sugar, freshly squeezed lime juice, and olive oil. Blend everything until as smooth as possible.

Remove the vanilla pod and pour the chilled vanilla base into the prepared ice cream maker. Churn according to the manufacturer's instructions until it reaches a soft-serve consistency.

Start with a layer of vanilla ice cream, followed by a spoonful of basil purée, then a layer of roasted strawberries. Repeat this sequence until all the ingredients are used up. The top layer should be vanilla ice cream again.

Using a thin knife or skewer, gently drag it through the layers in a zigzag motion so the flavors mingle slightly and create a marbled effect. Seal the container and freeze for several hours until fully set.