Homemade Tuna Salad

Name: Homemade Tuna Salad
Ingredients: 4 1/2 teaspoons sliced green onion tops (green parts only); 1 tablespoon chopped parsley leaves; 1/4 teaspoon celery seed; 1/4 teaspoon freshly ground black pepper; Lettuce cups or sliced bread; 1 tablespoon olive oil; 1 teaspoon kosher salt; 1/2 teaspoon freshly ground white pepper; 2 (12-ounce) portions tuna steak; 1/2 cup plus 1 tablespoon mayonnaise; 3 tablespoons finely chopped red onion; 6 tablespoons finely chopped celery; 1/4 cup sliced pimento stuffed green olives