Drain the canned 2 can canned tuna in water drained well thoroughly and add it to a medium Mixing Bowl. Break up any large chunks with a fork. Add the ⅓ cup mayonnaise, 2 tsp Dijon mustard, diced 2 stalks celery finely diced, 2 tbsp red onion finely diced, 1 tbsp fresh lemon juice, ¼ tsp kosher salt, and ¼ tsp black pepper freshly ground. Stir until evenly combined. Taste and adjust seasoning as needed.

Use sliced bread at room temperature for even results. For rolls or baguette-style loaves, slice in half lengthwise to expose more surface to the heat. For crispier French-style bread, lightly mist or rub the outside with water before loading it in. If adding cheese or toppings, have them ready to go. Position the rack in the center of the Toaster Oven before you start.

Preheat on the toast or bake setting. Toaster ovens run hotter and faster than full-size ovens, so ignore Oven timing. Standard sliced bread on a medium setting is done in 2 to 4 minutes depending on your model and slice thickness. Place bread directly on the rack or on a small Aluminum Foil-lined pan with space between pieces for even heat circulation. For rolls or French-style bread misted with water, set the temperature to 350°F to 375°F. The surface moisture creates a light steam effect that encourages a crisp exterior. Watch through the oven window rather than relying on a timer alone. Look for a deep golden-tan color. For a cheese melt, let the bread warm and lightly color first, then add cheese and continue until fully melted and bubbling. Use the broil function for even coverage. If the top browns too fast, loosely drape a small piece of foil over it to slow browning without stopping the cook.

Use sliced bread at room temperature for even results. For rolls or baguette-style loaves, slice in half lengthwise to expose more surface to the heat. For crispier French-style bread, lightly mist or rub the outside with water before loading it in. If adding 4 oz sharp cheddar cheese sliced or shredded or toppings, have them ready to go. Position the rack in the center of the Toaster Oven before you start.