Step 2

Meanwhile, put the eggs in a small pan of water, bring to the boil, then simmer for 8–10 minutes depending on how you like them cooked. Plunge into cold water to cool for a few minutes, then peel and halve.

Step 3

In a large salad bowl, whisk together the remaining oils, red wine vinegar, capers, and chopped tomatoes. Season, then add the onion, spinach, tuna, and potatoes and gently toss together. Top with the eggs and serve straight away.