Place the pine nuts, rosemary, half the tuna, anchovies, lemon and oil in a food processor. Process until smooth. Stir the sauce through the remaining tuna chunks.
Arrange the rocket onto plates.
Steam the asparagus for 2 - 3 minutes. Plunge in ice cold water and drain.
Place the asparagus onto the rocket and add the sauce.
Note: Asparagus belongs to the lily family. Its spears take up to 3 years to produce once planted but once it starts producing it will continue to for the next 20 years.