Begin by draining the tuna from two 5-ounce cans, then flake it into a medium-sized mixing bowl using a fork.

Fold in ½ cup of halved Kalamata olives, ¼ cup of crumbled feta cheese, and ¼ cup of finely diced red onion.

In a small bowl, whisk together 2 tablespoons of fresh lemon juice, 3 tablespoons of extra virgin olive oil, 1 teaspoon of dried oregano, ½ teaspoon of salt, and ¼ teaspoon of black pepper.

Pour the prepared vinaigrette over the tuna mixture and gently fold the ingredients together until evenly coated.

Serve immediately or chill for about one hour before enjoying.