Finely chop rocket and fry briefly in olive oil in a saucepan. Add the cream and bring to the boil. Purée finely with a hand blender, possibly push through a sieve. Scatter agar-agar and bring to the boil again. Stir well for 2 minutes. Season to taste with salt and lemon.
Chill in the refrigerator for approx. 2 hours until the mixture is firm enough to cut the lobes.
Goes well with tuna or beef tartare, as a spread with fresh ciabatta or