Make the dressing by blending all of the ingredients in a food processor (or very finely chop them), saving a few herb leaves for the salad. You can make the dressing up to 24 hrs before serving.

Scatter the beans and spinach over a large platter. Arrange the tomatoes, cucumber, mango, onion and radishes on top and gently toss together with your hands. Top the salad with the avocados, feta and herbs, and serve the dressing on the side.