Tuna Melt Baguette Recipe

Prepare tuna

Open and drain the canned tuna well. Transfer tuna to a medium mixing bowl and use a fork to flake into small pieces.

Add mayonnaise, Dijon mustard, minced red onion, diced celery, chopped capers, lemon juice, chopped parsley, salt, and black pepper to the bowl. Stir until ingredients are evenly combined but salad remains slightly chunky. Taste and adjust seasoning or lemon as desired. If you want a bit of heat, stir in optional hot sauce to taste.

Preheat the oven to 400°F (200°C) and position a rack in the center. Line a baking sheet with parchment if desired.

Slice the baguette in half lengthwise. Spread softened butter evenly on the cut sides of both halves. Lightly brush the outside crust with olive oil for extra crisping.

Place baguette halves cut-side up on the prepared baking sheet. If using tomato slices, arrange a single layer of tomato on the bottom half. Spoon the prepared tuna salad evenly over the bottom half of the baguette, leaving a small border at the edges so filling doesn’t spill when baking.

Top the tuna salad with arranged slices of Swiss or Gruyère cheese, covering the filling. Season tomato (if used) with a pinch of salt and freshly ground black pepper.

Bake the assembled baguette in the preheated oven for 8–10 minutes, or until the cheese is melted and the bread edges are golden. For a more browned, bubbly top, switch to broil on high for 1–2 minutes—watch closely to prevent burning.

Remove from oven and let rest 1 minute. Using a sharp serrated knife, slice the baguette into 4–6 portions. Sprinkle with chopped parsley and an extra grind of black pepper. Serve warm.