Simmer the lentils in a pan of boiling water for 20-25 minutes, until cooked; drain and set aside
Blanche the green beans in boiling water for 3-5 minutes until just tender; drain and cool under cold running water; leave aside
To make the salsa verde, process together, the rocket, mint, coriander, olive oil and lime juice until you get a chunky sauce
Mix the lentils, beans, tomatoes and celery together; put aside 2 tablespoons of the sauce in a bowl and add the rest to the vegetables; stir well to coat all the vegetables
Place on a serving dish and sprinkle with the lime zest and the rest of the salsa and serve
8 servings