Dissolve the jelly in very hot water according to packet directions and allow it to cool.
Put 4 tbsp of cooled (but still runny) jelly in a 1-liter glass bowl.
Top the jelly in the glass bowl with 5 slices of Swiss roll, and swirl around continuously until set.
Place the remaining slices of Swiss roll onto set jelly.
Whip the whipping cream until very thick and add the remaining cooled jelly.
Stir with a fork until well combined.
Spoon onto the Swiss roll layer and transfer to the fridge for about an hour and
a half, or until set.
You can serve with lemon rind, drizzled melted chocolate, and/or fresh raspberries for decoration.