Drain the canned tuna well.
Finely dice the celery, chop the walnuts, and slice the green onions.
Combine the tuna, celery, walnuts, green onions, mayonnaise, lemon juice, pepper, and salt in a bowl.
Stir to combine.
Serve as a sandwich, salad over a bed of greens, or with crackers and vegetables for dipping.
Refrigerate up to four days.
