Remove the mint chocolate chip ice cream from the freezer and leave to soften for 20-30 mins until it’s easy to scoop and mould. Spoon into a roughly 1.2-litre freezerproof bowl that's about 20cm in diameter at the top (if you don’t have a bowl this size, a larger one is fine – you will just have a wider, shorter bombe). Spread the ice cream all over the inside of the bowl to make a layer that's about 2-3cm thick. Return to the freezer for 30-45 mins to set again.

Around 20 mins after putting the bowl in the freezer, remove the chocolate ice cream from the freezer. Leave at room temperature for about 10 mins. Meanwhile, melt half the dark mint chocolate in a heatproof bowl over a pan of simmering water, ensuring the bowl doesn’t touch the water (or do this in the microwave in 10-second bursts), stirring until smooth. Once the mint chocolate chip ice cream has set (it’s fine if it’s still slightly soft), drizzle over the melted dark mint chocolate – it should set almost as soon as it touches the ice cream. Next, layer in the chocolate ice cream, ensuring it's in as even a layer as possible. Freeze again for another 30-45 mins to set.

Remove the vanilla ice cream from the freezer and set aside at room temperature for 20 mins, then melt the remaining dark mint chocolate in the same way as before towards the end of that time. Drizzle the melted chocolate over the chocolate ice cream layer, then fill the bowl to the top with the vanilla ice cream, smoothing the surface with a spatula. Return to the freezer for at least 3 hrs, or overnight.

When you’re ready to serve, melt the dark chocolate as before, then remove the bombe from the bowl by quickly dipping the bowl in hot water and inverting onto a plate. If the ice cream on the outside melts too much, return it to the freezer to set up slightly. Drizzle over the melted dark chocolate and decorate with your choice of mint chocolate pieces.