Best Tuna Melt Recipe

Ingredients

• 1/3 c. mayonnaise
• Juice of 1/2 lemon
• 1/2 tsp. crushed red pepper flakes (optional)
• 2 (6-oz.) cans tuna
• 1 celery ribs, finely chopped
• 2 dill pickles, finely chopped
• 1/4 c. finely chopped red onion
• 2 tbsp. finely chopped fresh parsley
• Kosher salt
• Freshly ground black pepper
• 4 tbsp. unsalted butter, softened
• 8 slices bread, such as sourdough
• 1 tomato, sliced
• 8 slices cheddar or American cheese