Ingredients (Serves 4)
For the dressing
Preheat the oven to 200°C, 400°F, Gas 6. Arrange the potatoes on a baking tray, drizzle with oil and toss to coat. Bake for 40 minutes. Cool then halve.
Blanch the beans in boiling water for 3 minutes, then rinse. Cover the eggs with cold water, bring to the boil and simmer for 6 minutes. Rinse, peel and quarter the eggs. Whisk together the dressing ingredients.
Heat a non-stick frying pan. Brush the tuna with oil then sear for 2-3 minutes on each side. Put the salad leaves into a bowl, add the onions, olives, beans and half the dressing. Divide between 4 plates, scatter over the potatoes, eggs and top with tuna drizzled with oil.
Serve the remaining dressing on the side.