Blanch the broad beans in boiling, slightly salted water for 3 minutes, then drain and rinse with cold water and set aside.
Cut off the ends of the radishes, then quarter or slice them. Finely slice the onion.
Dry-fry the cumin seeds for a couple of minutes until fragrant.
When the broad beans are cool, pop them out of their skin and toss with the radishes, onion , mint and in a serving dish. Scatter the cumin seeds and feta on tip. Season to taste. Toss.
Whisk the ingredients for the dressing in a small bowl and pour over the salad just before serving.
Garnish with salad cress or small mint leaves.