Take a large pot of boiling water with salt in it. Add potatoes and cook them for 15 minutes or till they get tender with some firmness. Drain them and cool them down.
In a large bowl, combine olives, parsley, onions, tuna, green beans and potatoes. Refrigerate them for 2 hours at least.
In a serving salad bowl, toss the greens with some vinaigrette. Top it with a refrigerated potato mixture. Top it with tomatoes, eggs, capers and anchovies.