1. The Vinaigrette: Whisk all the ingredients together.
2. Season to taste with salt and pepper.
3. Set aside.
4. The Salad: bring a large saucepan 2/3 full of water to a simmer.
5. Add the eggs, gently, bring back to a simmer and cook 8-10 minutes.
6. Remove the eggs and cool them immediately under cold water.
7. Tap them all over to break the shells, then peel them and cut lengthwise into quarters.
8. Return the water in the saucepan to a boil, add the potatoes, and boil until barely tender (the will cook more later), about 10 minutes.
9. Remove the potatoes from the water and let cool, then slice them in half.
10. Return the water to a boil and add a teaspoon of salt.
11. Add the green beans.
12. Boil until barely tender, about 2-3 minutes.
13. Drain and cool under cold water immediately to stop them cooking.
14. Put the tuna and the potatoe halves in a shallow dish and pour 1/4 c.
15. of the marinade over them, turning them so they are all well coated.
16. Heat your grill.
17. Keep the heat about medium.
18. Lay the potatoes on the grate and cook about 4-5 minutes per side, or until nice and golden brown all over.
19. Grill the tuna, turning only once, about 4-5 minutes total for rare, 6-8 minutes total for medium (rare is best, medium if you must-).
20. Slice the tuna across the grain into 1/4-inch thick slices.
21. On each plate arrange a few butter leaves, and scatter the olives over top.
22. Divide the eggs, beans, tomatoes and potatoes around the plate.
23. Fan the tuna slices on one side of the plate.
24. Drizzle the vinaigrette over top.
25. Serve at room temperature.