Ingredients:

  • 2 (5 oz / 142 g) cans tuna in water, drained (about 10 oz / 283 g drained total)
  • 1/4 cup mayonnaise (60 ml)
  • 1 tablespoon Dijon mustard (15 ml)
  • 1 tablespoon fresh lemon juice (15 ml)
  • 2 tablespoons finely diced red onion (about 20 g)
  • 1 stalk celery, finely diced (about 45 g)
  • 1 teaspoon capers, drained and chopped (optional) (5 g)
  • 1/2 teaspoon kosher salt (2.5 g) — adjust to taste
  • 1/4 teaspoon freshly ground black pepper (0.5 g)
  • 1–2 dashes hot sauce (optional)
  • 8 slices sturdy bread (sourdough, country loaf, or your choice) — each slice about 1/2-inch thick (about 480–560 g total)
  • 4 oz shredded cheddar or Swiss cheese (115 g) — about 1/4 cup shredded per sandwich (or 4–8 slices)
  • 2 tablespoons unsalted butter, softened (30 g), or mayonnaise for grilling
  • Thin slices of tomato, butter lettuce, or dill pickle slices (optional, for serving)

Instructions:

  1. Prepare tuna: open cans, drain thoroughly, and flake tuna into a mixing bowl with a fork until pieces are flaky and mostly uniform.
  2. Make tuna salad: add mayonnaise, Dijon, lemon juice, diced red onion, diced celery, capers (if using), salt, pepper, and hot sauce; combine until evenly coated and adjust seasoning to taste.
  3. Prepare bread and cheese: set sliced cheese aside or shred as needed. Butter one side of each slice of bread (butter-side will be the outside when grilling) or spread mayonnaise on the outside for a crisp, golden crust.
  4. Assemble sandwiches: place 4 slices butter-side down, divide tuna salad evenly among them, top each with shredded or sliced cheese and optional tomato or pickles, then place remaining bread slices butter-side up on top.
  5. Grill sandwiches: heat a skillet over medium-low to medium, place sandwiches in skillet (work in batches if needed), and cook about 3–4 minutes per side, pressing lightly with a spatula, until bread is golden brown and cheese is melted. If cheese is slow to melt, cover pan briefly 30–60 seconds; reduce heat if bread browns too quickly.
  6. Rest and serve: transfer sandwiches to a cutting board, let sit 1 minute to firm up, cut in half on the diagonal, and serve immediately with suggested sides such as tomato soup, salad, kettle chips, or pickles.