The Only Thing I Make With Leftover Fish Are These Fish Cakes Recipe

I made Cod Fish Cakes with capers, mustard and scallions and they come out crispy on the outside, herb-packed and bright enough to make you cancel takeout.

I’m obsessed with these fish cakes because they turn leftover dinner into something I actually crave. I love the mix of flaky 1 pound cooked fish, flaked (salmon, cod or haddock work great) and briny 2 tablespoons capers, roughly chopped that hit salty and bright in every bite.

These Cod Fish Recipes and this Fish Cakes Recipe are the ones I brag about but won’t share the exact reason why. They’re messy, juicy, and saucy.

And that tarragon mayo? Don’t skip it.

Seriously. It makes the whole thing sing.

You’ll lick your fingers, no shame. Every single time, I swear.

Ingredients

• Cooked fish: the protein and flaky heart of the cakes, super satisfying.
• Mashed potato: binds everything together, makes it cozy and not dry.
• Egg: it’s the glue that keeps the patties from falling apart.
• Panko: gives a light crunch, not greasy, you’ll love the texture.
• Dijon mustard: a tangy lift that keeps things from tasting flat.
• Capers: little briny pops that cut through the richness, bold bites.
• Scallions: fresh oniony snap, green color, brightens every mouthful.
• Parsley: clean herb freshness, makes the fish cakes feel lighter.
• Tarragon: anise-like hint, classy herbal note that pairs with fish.
• Lemon zest and juice: bright acid that wakes up the whole dish.
• Salt and pepper: simple seasoning that makes everything actually taste good.
• Oil for frying: gives golden crust and that craveable exterior.
• Mayo base: creamy backdrop for the tarragon, soothing and rich.
• Tarragon mayo mix: basically herb-forward sauce that’s tangy, smooth, perfect.

Ingredient Quantities

• 1 pound cooked fish, flaked (salmon, cod or haddock work great)
• 1 cup mashed potato or 1 large cooked russet, mashed roughly
• 1 large egg, lightly beaten
• 1/2 cup panko breadcrumbs plus extra for coating
• 2 tablespoons Dijon mustard
• 2 tablespoons capers, roughly chopped
• 3 scallions, thinly sliced (white and green parts)
• 2 tablespoons fresh parsley, chopped
• 1 tablespoon fresh tarragon, chopped
• 1 teaspoon lemon zest plus 1 tablespoon lemon juice
• 1/2 teaspoon kosher salt, more to taste
• 1/4 teaspoon black pepper
• 2 to 3 tablespoons vegetable oil or olive oil for frying
• For the tarragon mayo: 1/2 cup mayonnaise
• For the tarragon mayo: 2 tablespoons chopped fresh tarragon
• For the tarragon mayo: 1 teaspoon Dijon mustard
• For the tarragon mayo: 1 tablespoon lemon juice
• For the tarragon mayo: salt and pepper to taste

How to Make this

1. Make the tarragon mayo first so flavors marry: stir together 1/2 cup mayonnaise, 2 tablespoons chopped fresh tarragon, 1 teaspoon Dijon, 1 tablespoon lemon juice and salt and pepper to taste; chill while you make the cakes.

2. Flake 1 pound cooked fish into a big bowl, removing any skin and bones as you go; leave some chunkiness for texture.

3. Add 1 cup mashed potato (or one large cooked russet, roughly mashed), 1 large lightly beaten egg, 1/2 cup panko, 2 tablespoons Dijon mustard, 2 tablespoons chopped capers, 3 sliced scallions, 2 tablespoons chopped parsley, 1 tablespoon chopped tarragon, 1 teaspoon lemon zest, 1 tablespoon lemon juice, 1/2 teaspoon kosher salt and 1/4 teaspoon black pepper; fold gently until combined but dont overwork it or it gets gluey.

4. If the mixture feels too wet to shape, add a bit more panko, a tablespoon at a time; if too dry, wet your hands slightly or add a splash of lemon juice or a beaten egg white.

5. Shape the mixture into 8 medium patties or 6 larger ones, pressing them together so they hold, then coat both sides lightly with extra panko for a nice crunch.

6. Chill the patties for at least 20 minutes in the fridge so they firm up; this helps them hold while frying.

7. Heat 2 to 3 tablespoons vegetable or olive oil in a large skillet over medium heat until shimmering but not smoking; test with a few crumbs of panko, they should sizzle.

8. Fry the cakes in batches, about 3 to 4 minutes per side, until golden brown and heated through; flip carefully with a spatula so they dont fall apart. Add a little more oil between batches if the pan looks dry.

9. Drain briefly on paper towels and season with a tiny extra pinch of salt while hot; keep them in a warm oven if making a bunch.

10. Serve warm with the chilled tarragon mayo spooned on top or on the side, garnish with extra scallions, parsley or lemon wedges and enjoy.

Equipment Needed

1. Large mixing bowl for flaking and combining the fish — wait sorry dont use that symbol, use a big bowl for everything
2. Measuring cups and spoons (1/2 cup, tablespoons, teaspoons)
3. Potato masher or fork to rough mash the potato
4. Whisk or fork for beating the egg and mixing the mayo
5. Spatula and a slotted spatula for flipping the cakes
6. Large nonstick or stainless skillet for frying
7. Baking sheet or plate lined with parchment or foil to chill the patties
8. Paper towels and tongs for draining and handling hot cakes

FAQ

The Only Thing I Make With Leftover Fish Are These Fish Cakes Recipe Substitutions and Variations

• Cooked fish (salmon, cod or haddock): substitute canned salmon or tuna for convenience or cooked shrimp for a sweeter flavor. Canned works fine if you drain well and flake out bones.
• Mashed potato or cooked russet: swap in cooked sweet potato or 1 cup cooked rice for a different texture and a bit more fiber. Sweet potato will make them slightly sweeter, rice gives a looser binder so press cakes firmer.
• Panko breadcrumbs: use crushed saltine crackers, plain breadcrumbs, or ground cornflakes. Any of these give crunch but adjust salt because crackers can be salty.
• Mayonnaise in the tarragon mayo: use Greek yogurt or sour cream for a tangier, lighter sauce. If you use yogurt, taste and add a little oil if you want it richer.

Pro Tips

1. Chill the patties longer than you think. Letting them sit 30 to 45 minutes firms them up so they dont fall apart when you flip, and it also helps the panko coating stick better.

2. Control moisture, not just with panko. If the mix feels wet, press out extra water from the mashed potato with a towel or add panko a tablespoon at a time. If its too dry, wet your hands or fold in a beaten egg white so the cakes stay tender.

3. Get the oil temp right. Medium heat that shimmers but is not smoking is perfect. Too hot and the outside burns before the center warms; too cool and they soak up oil and get greasy. Test with a few panko crumbs so you dont overdo it.

4. Finish in the oven when making a lot. Fry just to golden, then transfer to a 250 F oven to keep warm without drying. This also lets you cook batches ahead and serve everything hot at once.