Prep the tuna salad: In a medium bowl, mix the tuna, carrots, celery, red onion, and Dijon mustard. Season with salt and pepper to taste. Set aside.
Build the platter: Choose a large board or shallow serving tray. Add the bowl of tuna salad to the center or off to one side.
Arrange the vegetables: Layer butter lettuce, arugula, tomatoes, and blanched green beans around the tuna. Scatter the halved eggs over the top.
Serve: Drizzle dressing over the greens or serve on the side. Add optional extras like olives, capers, or boiled potatoes if you like.
I’m a big fan of the Italian flaked tuna in olive oil. It’s a splurge and it has more calories BUT it is full of flavor and since I do not use mayonnaise this recipe requires some fat. If you use tuna in water I suggest adding about a tablespoon of olive oil to this recipe for moisture.