Ingredients
- 1 (5 oz) can white albacore tuna packed in water, drained
- 1 1⁄2 Tbsp mayonnaise
- 1 tsp Dijon mustard
- 1⁄8 tsp ground celery seed
- 2 Tbsp sliced pitted black olives
- 2⁄3 cup green leaf lettuce
- 4 slices whole-wheat bread
- 2 slices Swiss cheese
- 4 slices red onion