1. Put potatoes in a pan of lightly salted water. Bring to the boil then simmer until potatoes are just cooked. Drain and refresh under cold water. Set aside.
2. Cook beans in lightly salted water until just cooked. Drain and refresh under cold water. Set aside.
3. Put black eyed beans, chickpeas, spring onions, green chilli, tomatoes and mint leaves in a bowl and mix well.
4. Fold in potatoes and green beans.
5. Combine all dressing ingredients.
6. Pour dressing over salad and toss well.