2.Cook pasta in large saucepan of boiling water until just tender; drain.
3.Halve fish fillets. Bring the water and lemon to the boil in large frying pan. Add fish; simmer, uncovered, until fish is cooked, drain. Cut fish into chunks.
4.Combine pasta, onion, capers, tomato, cucumber, rind and juice in large bowl. Add fish and pesto; toss gently to combine.
5.Blend or process rocket, cheese, nuts and garlic until smooth. With motor operating, add oil in a thin, steady stream until pesto thickens.
Farfalle is a short, rather sturdy butterfly-shaped pasta that is also known as “bow-ties”. It is good for a dish such as this because the folds and crinkles of each piece help capture the pesto and hold the other ingredients. Replace the farfalle with penne or small shells if you wish.