How to Make a Tuna Melt

Details

Ingredients

• 1 (6.5 ounce) jar oil-packed tuna, drained
• 1 tablespoon minced green onion
• 2 tablespoons finely diced celery
• 2 teaspoons capers, drained
• 1 teaspoon Asian chile paste (such as sambal oelek)
• 2 tablespoons mayonnaise, or more to taste
• ⅓ cup fresh mozzarella cheese
• salt and ground black pepper to taste
• 2 tablespoons softened butter, divided
• 2 thick slices French bread
• ¼ cup shredded sharp white Cheddar cheese, divided
• 1 pinch cayenne pepper, or to taste