Why It Works
- Briefly soaking the diced red onion in red wine vinegar tames its pungency and gives it a pop of tartness.
- Shredding the tuna finely prevents the salad from ending up with any dry bits.
- A splash of fish sauce or minced anchovy adds a subtle savory hit.
Classic in every way, but with a couple of subtle twists to amp up its flavor and texture, the tuna salad on these sandwiches is packed with bits of celery, rapid-pickled red onion, parsley, and a small dose of fish sauce (or anchovy) for a deeper, more savory flavor.
- 1 medium red onion (about 8 ounces; 225g), cut into 1/4-inch dice
- 1/2 cup (120ml) red wine vinegar
- 4 (5-ounce; 140g) cans oil-packed tuna, drained
- 1 cup (240ml) mayonnaise, plus more as needed
- 2 stalks celery (about 6 ounces; 170g total), cut into 1/4-inch dice
- 1 ounce (about 10 stalks) flat-leaf parsley leaves and tender stems, minced (about 1/4 packed cup)
- 1/2 teaspoon (3g) Asian fish sauce or very finely minced oil-packed anchovy fillets (about 2 small fillets)
- Kosher salt and freshly ground black pepper
- 8 slices sandwich bread, very lightly toasted
- Romaine lettuce leaves, torn, for garnish
In a small bowl, combine onion and vinegar (vinegar should just cover onion; add more if it does not) and let stand 15 minutes.
Meanwhile, in a medium bowl, combine tuna and mayonnaise and mix very well with a spoon until tuna is reduced to very small shreds.
Drain onion well, then add to tuna along with celery, parsley, and fish sauce or anchovy. Mix until well incorporated, then season with salt and pepper. Add more mayo, 1 tablespoon at a time, if desired.
Spoon tuna salad onto 4 bread slices, top with lettuce leaves, then close sandwiches. Serve right away.