• Clean the potatoes and place in a medium-large pot. Add cold water to cover the potatoes with a good inch/3cm or more extra water then cover with a lid and place on a medium-high heat to bring to a boil. Reduce the heat so the water is at a steady but gentle boil. Let cook around 10-15 minutes until the potatoes are tender to a knifepoint. Then, drain the potatoes and allow to cool slightly.
• As potatoes are cooking, place the eggs in a small pan and cover with cold water. Cover and place on a medium-low heat and warm until just about to boil. Then, remove the pan from the heat and leave the eggs in the hot water for 4 minutes. After this time, carefully remove the eggs with tongs to a bowl of ice water and leave to cool in the water before peeling the shells off. (See notes)
• Also meanwhile, bring a pot of water to the boil to cook the beans. Gently salt the boiling water, add the beans and cook around 1-2 minutes until they are just starting to soften. Remove from the hot water and place in a bowl with iced water. After a minute or two, drain and set aside.
• Once the potatoes are cool enough to handle, cut them into halves or quarters, depending on size. If you prefer, you can also peel off the skins but you can also leave them on, if you like. Place the potatoes in a bowl.
• Halve the tomatoes and add them to the bowl with the potatoes. Halve the cooled beans (unless already short) and add them in with the potatoes and tomatoes.
• Trim the ends from the romaine lettuce then cut into relatively thin slices. Place the sliced lettuce in a separate bowl.

For vinaigrette and to serve

• Finely chop and slightly mash the anchovies and place in a small bowl or small jar.
• Add the rest of the vinaigrette ingredients, apart from the basil, and if in a bowl, whisk together. to blend Alternatively, if in a small jar, shake together. Tear the basil leaves into small pieces and mix into the blended up vinaigrette.
• Add a few tablespoons of the vinaigrette (around ⅓ to ½ of the total) to the lettuce and toss to coat the leaves evenly.
• Add the remaining vinaigrette to the bowl with the potatoes, tomatoes and beans and toss gently to coat.
• Divide the lettuce between four plates (or more for smaller servings) then top with some of the potato/tomato/bean mixture. Drain the tuna, flake it and add some on top of each plate. Add a few olives on top as well.
• Cut the peeled eggs into quarters and place two wedges on the side of each plate and serve, garnished with extra basil if you like.