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Po'Boy Sandwiches lined up on a cutting board.

Crispy Fish Po'boy Sandwiches with Lemon Tarragon Mayo

These Crispy Fish Po'boy Sandwiches are slathered with lemon tarragon mayo and stuffed with tomatoes, lettuce, pickles, and homemade fish cakes.
Course Main Course
Cuisine Pescatarian, Pescetarian, Seafood
Keyword fish, king oscar, Poboy, Sandwich, Sardines, seafood
Author Dana Sandonato


  • Cast iron skillet or non-stick frying pan
  • Plate or baking sheet
  • Paper towels
  • Tongs


Fish cakes.

  • 2 cans of King Oscar Skinless Boneless Sardines in Olive Oil, drained
  • 1/4 cup olive oil
  • Zest of one lemon
  • 1 tsp Dijon mustard
  • 1/2 tsp Old Bay seasoning Or 1/4 tsp kosher salt
  • Cracked black pepper, to taste
  • 1 large egg, lightly beaten
  • 1 cup panko bread crumbs

Lemon Tarragon Mayo.

  • 1/2 cup mayonnaise
  • 1/2 TBSP freshly squeezed lemon juice, more to taste if needed
  • 1.5 TBSP dried tarragon You could use freshly chopped tarragon, but the flavor may not come through as strongly; add more as needed.


  • 4 fresh French rolls or hoagies
  • Lettuce, sliced into ribbons
  • Tomato slices
  • Bread and butter pickles You can also use dill pickle if you prefer
  • 4 TBSP butter


Lemon Tarragon Mayo.

  • Transfer 1/2 cup of mayo to a medium-sized bowl. While whisking, slowly drizzle the lemon juice into the mayo bit by bit. You don't want your mayo to lose consistency and become liquidy. Taste it. If it's still a thick consistency and you'd like more lemon flavor, go ahead and slowly whisk in a bit more lemon juice. Stir in the dried tarragon and set aside in the fridge until ready for use.

Fish cakes.

  • Put the panko bread crumbs into a bowl and set aside.
  • Transfer the drained sardines into a large bowl. Mash them with a fork to break the meat into a flaky consistency. Add the lemon zest, Dijon mustard, Old Bay seasoning, and cracked pepper. Stir the mixture until it's well blended. Give it a taste and season with Old Bay (or salt) and pepper as needed. Finally, add the beaten egg and mix until well combined.
  • Form the fish cakes into bite-sized morsels (about 1 inch long and 1/2 inch thick, give or take) and roll them into the panko bread crumbs, covering them entirely. Place the breaded morsels onto a place or baking sheet until you're done. This recipe should make about 18 little fish cakes.
  • Heat olive oil in a skillet over medium-high heat. Once the oil is shimmering, carefully place some fish cakes into the pan. Put down as many as you can fit without overcrowding the pan. Let the cakes simmer for about 1-2 minutes each side, turning them carefully with tongs, until breading is golden brown and crispy. When done, carefully remove the fish cakes and place them onto a paper towel-lined plate or baking sheet to absorb excess oil.
  • When done, let the fish cakes set on the paper towels for about 5-10 minutes. They'll become more sturdy as they sit. In the meantime, prepare your rolls.


  • (Toasting your rolls is optional. If not toasting them, skip this part.) Slice your rolls open and butter the inside generously. Place the buttered sides down into a hot pan (you can use the one you used to cook the fish cakes if you'd like; the bread will soak up that extra flavor) until the inside of the bread is lightly golden brown and toasty.
  • Slather the lemon tarragon mayo over the inside of each roll. Then stuff with ribboned lettuce, tomato slices, and pickle slices. Finally, stuff your fish cakes inside.


If you have leftover fish cakes, they will keep in the fridge for three days—and they taste great cold as a quick snack!