10-12 oz. good quality canned tuna packed in Olive Oil.
1/4 cup mayo or light mayo
1 tsp. Dijon mustard
1 T lemon juice
1/4 tsp. celery seed
1/4 tsp. salt or substitute
1/2 cup finely chopped celery
1 T capers, chopped
2 green onions, thinly sliced
8 large lettuce leaves, washed and dried (romaine, iceberg or butter lettuce will work for this)
1/2 cup chopped cherry tomatoes (optional)
Drain tuna into a fine-mesh strainer and press down to drain out the oil (or water if you use water-packed tuna.) While tuna drains stir together the mayo, Dijon, lemon juice, celery seed, and salt.
Cut lettuce apart and pick out 8 large leaves. (use two heads of romaine and keep the smaller inner leaves for salad greens.) Wash lettuce and spin dry in a salad spinner or dry with paper towels. Chop the celery and capers and thinly slice the green onions. Chop tomatoes if using.
When the tuna has drained, put it in a bowl (with a snap-tight lid if you won't be eating it all at once.) Stir in the dressing until it's well-distributed in the tuna, then mix in the celery, capers, and green onions.
Fill lettuce leaves with the tuna mixture, garnish with cherry tomatoes, and eat with your hands.
This kept well in the fridge for several days.