Preparing the tuna: Place the tuna cubes in a bowl.
Mixing the ingredients: In the bowl with the tuna, add the black olives, capers, lemon juice, parsley and olive oil. Season with salt and pepper to taste. Mix gently to coat the tuna with all the ingredients.
Serving: Serve the tuna tartare very fresh, accompanied by slices of toasted baguette for a crispy texture. You can also present it with a rocket salad for a touch of freshness.