Onion and tuna salad is a fresh and simple dish, perfect for summer and for those seeking a light yet nutritious meal. This dish combines the intensity of red onions with the flavor of tuna, creating a balance that suits various occasions. It's a great choice for a tasty appetizer or a main dish to take to the beach or for a picnic. The preparation requires few, easily available seasonal ingredients, making this recipe accessible to everyone. Originating from Italian culinary tradition, onion and tuna salad is particularly popular in coastal regions where fresh fish is always available. However, each family can personalize it with variations including ingredients like cucumbers, bell peppers, or fresh herbs. Each version brings a regional touch that enriches the basic recipe. Pairing onion and tuna salad with a good chilled white wine, such as Vermentino or Sauvignon Blanc, further enhances the flavors of the dish. Additionally, serving it with Tuscan bread croutons or focaccia makes it even more inviting, transforming a simple dish into a moment of shared enjoyment.

Start by thoroughly washing the Tropea onions, then peel and slice them thinly, aiming for even slices. Place the onion slices in a bowl and to tone down their sharpness, let them soak in cold water for about 10 minutes, then drain. Meanwhile, wash the salad greens under running water and dry them using a salad spinner or by gently patting with a clean kitchen towel. In a large salad bowl, combine the salad greens, sliced onions, drained and flaked tuna, and halved cherry tomatoes. Add pitted black olives and gently mix to combine the ingredients without breaking them. Drizzle with extra virgin olive oil to taste, a splash of white wine vinegar, salt, and pepper, adjusting to your preference. Toss again to evenly distribute the dressing and let the salad rest for a few minutes before serving to allow the flavors to meld.