Line a glass bowl with cling film so it comes over the edges.
Take out ice-cream from freezer so it's not too hard when using later.
Cut the swiss roll into 1.5cm slices
Place the slices of swiss roll around the bowl, starting from the centre. Make sure the nicest side of the swiss roll slice is up against the cling film. If you have gaps that need filling, cut the slices of the swiss roll into halves or quarters and fill in the gaps.
Brush the inside of the swiss roll with sherry.
Scoop ice-cream into the centre of the swiss roll until full. Use a palette knife to smooth the base so it's even.
Pop into the freezer for an hour and take out when you are ready to serve.