1To make the vinaigrette, whisk together mustard, vinegar and oil until well combined. Season with salt and pepper, then set aside.
2Put the potatoes in a large saucepan. Cover with cold water. Bring to the boil over high heat. Reduce heat to medium and cook, for 20 minutes until tender when pierced with a skewer. Drain, then cut into slices.
3Meanwhile, fill the pot of the Precision Poacher with water up to the STEAM fill line. Put the beans onto the tray, spreading out evenly and lower into the pot. Cover with the lid.
4Press METHOD button to select STEAM. Press TIME button to select 3 minutes. Press START. Once finished refresh the beans under cold running water. Set aside.
5Fill the pot of the Precision Poacher with water up to the STEAM fill line. Place the eggs onto the egg tray and lower them into the pot. Cover with the lid.
6Press METHOD button to select STEAM. Press TEXTURE button to select MEDIUM. Press START. Once finished cool eggs under cold running water, then set aside. When cool enough to handle, peel and cut in half lengthwise.
7Preheat a large non-stick skillet over medium heat. Sear the tuna for 20-30 seconds on each side for medium-rare or cook to your liking. Transfer to a cutting board, then thinly slice.
8Divide the lettuce, tomatoes, olives, tuna, eggs and beans among the serving plates. Drizzle with the vinaigrette and season. Serve