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Tuna Melts with Quick-Pickled Fennel

Tuna Melts with Quick-Pickled Fennel

Tuna melts with quick-pickled fennel is an elevated version of the diner classic, bringing bright herbaceous flavors to the forefront. Enjoy as an easy, make-ahead lunch or weeknight dinner.
Course Entree
Cuisine American
Prep Time 15 minutes
Cook Time 5 minutes
Total Time 20 minutes
Servings 5


  • 1 small fennel bulb thinly sliced, plus 1 Tbsp. chopped fennel fronds
  • 1/2 cup rice vinegar
  • 1 1/2 Tbsp. granulated sugar
  • 1 1/2 tsp. kosher salt divided
  • 2 5-oz. cans tuna in water, drained
  • 3 Tbsp. mayonnaise or whole-milk Greek yogurt
  • 1 tsp. Dijon mustard
  • Zest and juice of 1 lemon
  • 2 Tbsp. chopped fresh parsley
  • 2 tsp. capers drained
  • 1/2 tsp. freshly ground black pepper
  • 5 slices whole-grain bread
  • 1 cup freshly grated mozzarella cheese


  • Place fennel in large glass jar or measuring cup. Bring 1 cup water, vinegar, sugar, and 1 tsp. of the salt to a boil in a medium saucepan, whisking to dissolve sugar and salt. Pour liquid over fennel and set aside to cool to room temperature.
  • Combine tuna, mayonnaise, mustard, lemon zest and juice, parsley, capers, remaining 1/2 tsp. salt, black pepper, and fennel fronds in a bowl; stir well. Spoon tuna mixture evenly onto bread slices. Top with grated cheese. Broil on HIGH 2 to 3 minutes, watching closely to not burn, until cheese is melted and crust is golden.
  • Top tuna melts evenly with pickled fennel. Garnish with additional fresh herbs, if desired.