How to Make It
In a large saucepan, cover the potatoes with 1 1/2 inches of water and add a large pinch of salt. Bring to a boil and simmer the potatoes over moderately high heat for 10 minutes.
Meanwhile, put the green beans in a strainer, lower it into the simmering water in the saucepan and cook until just tender, about 4 minutes; transfer the beans to a plate to cool. Check the potatoes; they should be tender a few minutes after the beans are done. Drain and halve the potatoes, then let them cool.
In a small bowl, whisk the extra-virgin olive oil with the vinegar, parsley, tarragon, garlic, mustard and lemon juice and season with salt and pepper.
In a medium skillet, heat the pure olive oil. Season the tuna steaks with salt and pepper and dust with the fennel pollen. Cook the tuna over high heat until browned on the outside and rare within, about 1 1/2 minutes per side. Transfer to a plate and refrigerate until slightly chilled.
In a large bowl, toss the mesclun with the potatoes, green beans, anchovies, cherry tomatoes, olives, chives and capers. Add 1/4 cup plus 2 tablespoons of the vinaigrette and toss to coat.
Mound the salad on plates. Slice the tuna 1/3 inch thick and set on top of the salads. Surround with the eggs. Scatter the nasturtiums around the plates and serve, passing the remaining vinaigrette at the table to dress the tuna.
Fennel pollen is available at specialty food shops and from Sugar Ranch; 800-821-5989 or fennelpollen.com.