These golden crispy fish croquettes are the perfect holiday appetizer. Serve them with a tangy mustard sauce for a little extra oomph!

Close up plate if crispy fish croquettes garnished with chives.

This post is sponsored by King Oscar | Thank you for supporting the brands I trust.

Tasty snacks, because we deserve them.

The year 2020 has robbed us of a lot, and with the holiday season upon us, it’s sad to know it’s not done. Entertaining will be very different this year—maybe even non-existent for some! But let’s not rob ourselves of the delicious nosh that comes with it. It’s been a tough one, and we deserve the indulgence. We’ve earned it. With that, I’m urging you to put these crispy fish croquettes on your list of holiday quarantine appetizers.

Bind it, fry it, crunch it.

A croquette—the name deriving from the French word for crunch—is a small snack made up of a filling and binder, which is then breaded and deep-fried. A pretty broad illustration, I know. But you can make many different croquettes with various meats and binders. The binder, which keeps the croquettes from falling apart, is usually a thickening agent like bread crumbs, flour, a hearty béchamel, or like I’ve used here, mashed potatoes. When it comes to the star ingredient, you can use meats, seafood, cheeses, vegetables, rice, etc. So the croquette isn’t very specific in its ingredients—it’s more of a style.

I typically bake things rather than fry them, but for this recipe, baking doesn’t yield the proper crisp for a good croquette. So see this as a treat.

Glass mixing bowl filled with croquette filling ingredients before being mixed.

Crispy fish croquettes bring sardines to a new level.

This croquette recipe truly has it all: mashed potatoes, savory cooked onions, crunchy celery, and King Oscar’s Brisling Sardines in Zesty Tomato Sauce. All rolled up into a golden crisp nugget of goodness. These crunchy gems can be enjoyed on their own, but I’m a sucker for a good dip, so I made a tangy mustard sauce to serve with them.

I often opt for King Oscar’s sardines when creating a recipe with canned fish because they’re such a high-quality product and they bring so much flavor. The brand offers up a world of options from Mediterranean-style to these saucy tomato-packed fillets. The good news? If you can’t find King Oscar’s Brisling Sardines in Zesty Tomato Sauce at your local grocer, any of King Oscar’s sardines will work. It’s also worth mentioning that King Oscar has a shop on Amazon, so you can easily get your fix!

Sheet pan covered in parchment topped with uncooked croquette balls.

Serving platter full of crispy fish croquettes next to a tin of King Oscar sardines.

Making fish croquettes is easy.

The prep is a cinch, the formation is simple, and if you’re not used to deep frying, I’ve got an approachable way to do it.

Here’s what you’ll need:

  • White or yellow onion
  • Leftover mashed potatoes, cold
  • Celery
  • Fresh parsley
  • King Oscar Sardines in Zesty Tomato Sauce
  • Fresh chives
  • Kosher salt
  • Black pepper
  • Avocado oil or olive oil (an oil with a high smoke point)
  • All Purpose flour
  • Eggs
  • Panko bread crumbs

Here’s what you’ll do:

  1. Heat a drizzle of olive oil in a small pan. Once the oil is hot, add the onions and let them cook until their sweating and translucent, about five minutes. Remove the pan from the heat and set aside to cool.
  2. Get a deep skillet or Dutch oven and fill it with your chosen cooking oil until it’s about 1.5 to 2 inches deep. You only need enough to cover your croquettes. If it doesn’t fully cover your croquettes, you can turn them over during frying time. You can test whether or not the oil is hot enough for deep frying by sprinkling a few bread crumbs into it. If it sizzles and spits, the oil is ready. If not, try the bread crumb test again in a few minutes.
  3. While the oil heats up, get yourself a large mixing bowl. Into it, you’ll put the cooked onions, cold mashed potatoes, celery, parsley, sardines, chives, salt, and pepper. Mix the ingredients until they’re well blended.
  4. Place a sheet of parchment paper over a sheet pan. Scoop up about a tablespoon worth of the potato mixture  and carefully shape it into a ball. Carefully roll the ball through the flour, shaking off excess flour; dip the ball into the beaten egg, then roll it through the bread crumbs. Set it on to the parchment-covered sheet pan, and repeat until you’ve used up all of the mixture. This recipe should get you about 20 croquettes.
  5. Carefully transfer a croquette into the hot oil with a skimmer spoon or with tongs. Repeat until you’ve got as many croquettes in the pan as you can fit without overcrowding them. Deep fry the croquettes until the breadcrumbs have turned into a crispy golden crust—about 30 seconds. If the croquettes don’t fully immerse into the oil (because the oil isn’t deep enough), simply turn them over halfway through cooking time.
  6. When the croquettes have developed a nice golden crisp, remove them from the oil using the skimmer or tongs, and place on a paper towel-covered plate; the paper towels will soak up excess oil. Do this until all of the croquettes are cooked.
  7. Garnish with freshly chopped chives and serve with tangy mustard sauce.

Got leftovers? These croquettes will keep in the fridge for up to five days—and they’re tasty cold!

Overhead shot of serving plate of crispy fish croquettes with package of King Oscar sardines next to it.

side shot close up of plate of crispy fish croquettes with a bite taken out of one.

Here are some other great ways to use sardines:

Hope you enjoy!

If you plan on making this recipe, be sure to snap a pic and tag us on Insta! @killing__thyme.

Serving platter full of crispy fish croquettes next to a tin of King Oscar sardines.

Crispy Fish Croquettes

These golden crispy fish croquettes are the perfect holiday appetizer. Serve them with a tangy mustard sauce for a little extra oomph!
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Prep Time: 10 minutes
Cook Time: 25 minutes
Total Time: 35 minutes
Servings: 20 croquettes

Equipment

  • Deep pan or Dutch oven, for deep frying
  • Tongs
  • Skimmer spoon (optional)
  • Paper towels
  • Parchment paper

Ingredients

  • 1 tin of King Oscar's Brisling Sardines in Zesty Tomato Sauce However, any of King Oscar's sardines will work in this recipe.
  • 2 cups leftover mashed potatoes, cold
  • 1/2 cup diced white onion, sauteed and cooled
  • 1 rib of celery, minced
  • 2 TBSP chopped fresh parsley
  • 2 TBSP chopped fresh chives, plus more for garnish
  • 1/4 tsp kosher salt
  • 1/4 tsp cracked pepper
  • 1 cup all purpose flour
  • 2 eggs, beaten
  • 2 cups panko bread crumbs
  • Oil, for frying Use an oil with a high smoke point, like olive oil (not extra virgin olive oil) or avocado oil.

Tangy Mustard Sauce.

  • 1/3 cup plain Greek yogurt
  • 1 tsp Dijon mustard
  • 1/4 tsp garlic powder
  • 1/2 tsp freshly squeezed lemon juice
  • 1 TBSP freshly chopped chives
  • Pinch of kosher salt

Instructions

  • Heat a drizzle of olive oil in a small pan. Once the oil is hot, add the onions and let them cook until their sweating and translucent, about five minutes. Remove the pan from the heat and set aside to cool.
  • Get a deep skillet or Dutch oven and fill it with your chosen cooking oil until it’s about 1.5 to 2 inches deep. You only need enough to cover your croquettes. If it doesn’t fully cover your croquettes, you can turn them over during frying time. You can test whether or not the oil is hot enough for deep frying by sprinkling a few bread crumbs into it. If it sizzles and spits, the oil is ready. If not, try the bread crumb test again in a few minutes.
  • While the oil heats up, get yourself a large mixing bowl. Into it, you’ll put the cooked onions, cold mashed potatoes, celery, parsley, sardines, chives, salt, and pepper. Mix the ingredients until they’re well blended.
  • Place a sheet of parchment paper over a sheet pan. Scoop up about a tablespoon worth of the potato mixture  and carefully shape it into a ball. Carefully roll the ball through the flour, shaking off excess flour; dip the ball into the beaten egg, then roll it through the bread crumbs. Set it on to the parchment-covered sheet pan, and repeat until you’ve used up all of the mixture. This recipe should get you about 20 croquettes.
  • Carefully transfer a croquette into the hot oil with a skimmer spoon or with tongs. Repeat until you’ve got as many croquettes in the pan as you can fit without overcrowding them. Deep fry the croquettes until the breadcrumbs have turned into a crispy golden crust—about 30 seconds. If the croquettes don’t fully immerse into the oil (because the oil isn’t deep enough), simply turn them over halfway through cooking time.When the croquettes have developed a nice golden crisp, remove them from the oil using the skimmer or tongs, and place on a paper towel-covered plate; the paper towels will soak up excess oil. Do this until all of the croquettes are cooked.
  • Garnish with freshly chopped chives and serve with tangy mustard sauce.

Notes

Store leftovers in an air-tight container in the fridge for up to five days.