Step by step

Method

4 steps

1. 1

   In a bowl, mix two 5-oz cans tuna (drained well), ¼ cup mayonnaise, 1 finely diced celery stalk, 2 tablespoons diced red onion, 1 teaspoon lemon juice, and ¼ teaspoon black pepper until creamy and evenly combined — you want little crunch from the celery, not a wet mush.

2. 2

   Butter one side of each of 8 slices rye or sourdough with about 2 tablespoons unsalted butter total. Build 4 sandwiches: unbuttered side down, tuna salad, 1 slice cheddar, then the top slice buttered-side out.

3. 3

   Cook in a skillet over medium-low heat 3–4 minutes per side, pressing gently, until the bread is deep golden and crisp and the cheese is fully melted. Don't crank the heat or the bread burns before the cheddar softens.

4. 4

   Rest 2 minutes so the filling settles, then cut and serve. You want a crisp tuna melt with gooey cheddar and creamy tuna salad — not soggy bread or a cold cheese center.