Blackened Fish Tacos

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Yay tacos! Fish tacos! Fish tacos are one of my favorite foods in this whole world. To be honest, I love crispy fish tacos with lots of lime crema drizzled over it. But lately I’ve really been loving the simplicity of these blackened fish tacos in my repertoire.

Crispy keto fish tacos require some finessing to get a good light crust going. Sometimes I can’t be bothered with all that. These come in clutch for those days when I want my beloved keto tacos without the extra work of breading my fish.

Blackened Fish Tacos

I use a lot of my taco seasoning on everything and this is no different. There are only slight adjustments to make it a great seasoning for blackening fish. For the seasoning, you’ll need:

  • 1 T. onion powder
  • 1 T. garlic powder
  • 1½ T. smoked paprika
  • 1 T. dried thyme
  • 1 T. dried oregano
  • 2 t. sea salt
  • 1 t. black pepper
  • ½ t. – 1 t. cayenne pepper*

* Adjust the amount of cayenne to reach your desired level of heat. I love spicy tacos. You can easily double this recipe and store it in an airtight jar so you’ll always have delicious taco seasoning on hand.

To assemble your fish tacos, you’ll need

  • 2 T. extra virgin olive oil
  • 18-20 oz. mahi-mahi or another firm white fish (I use snapper fillets here in Jamaica)
  • 4-5 large radishes, trimmed and thinly sliced
  • 3 T. fresh cilantro leaves, chopped
  • 8 8-inch keto-friendly tortillas

I also LOVE this avocado ranch sauce over these tacos. It’s amazing.

Blackened Fish Tacos with Avocado Cream SaucePin

Keto Coleslaw

So of course you could grab a bag of coleslaw mix from the supermarket (this broccoli slaw is a fave) and call it a day. That will cut down on prep time so you can get to your tacos quicker. But if you want to make your coleslaw from scratch, here’s how to do it.

  • 3 c. green cabbage, thinly sliced
  • 1 c. red cabbage, thinly sliced
  • Optional: ½ c. kale leaves, finely chopped
  • 1 large carrot, shredded
  • 1/3 c. Greek yogurt
  • 1 T. apple cider vinegar
  • 1 t. keto sweetener
  • ¾ t. ground cumin
  • ¾ t. spicy Dijon mustard
  • 1 T. fresh lime juice
  • Sea salt and black pepper, to taste

It’s a good idea to mix the sauce ingredients well in advance, pour it over your thinly sliced veggies, cover it, and allow your coleslaw to chill out in the fridge so all those ingredients can soak into each other and get nice and happy together.

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Blackened Fish Tacos

Delicious keto-friendly fish tacos!
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Course: Main Course
Cuisine: American
Prep Time: 20 minutes
Cook Time: 8 minutes
Total Time: 28 minutes
Servings: 4
Calories: 322kcal
Author: Iva Ursano


  • Blackened Seasoning Ingredients:
  • 1 tbsp onion powder
  • 1 tbsp garlic powder
  • tbsp smoked paprika
  • 1 tbsp dried thyme
  • 1 tbsp dried oregano
  • 2 tsp sea salt
  • 1 tsp black pepper
  • ½ tsp – 1 t. cayenne pepper*
  • * Adjust amount of cayenne to reach desired level of heat
  • Coleslaw Ingredients:
  • 3 c. green cabbage thinly sliced
  • 1 c. red cabbage thinly sliced
  • Optional: ½ c. kale leaves finely chopped
  • 1 large carrot shredded
  • 1/3 c. Greek yogurt
  • 1 tsp keto sweetener
  • 1 tbsp apple cider vinegar
  • ¾ tsp ground cumin
  • ¾ tsp spicy Dijon mustard
  • 1 tbsp fresh lime juice
  • Sea salt and black pepper to taste
  • Remaining Ingredients:
  • 2 tbsp extra virgin olive oil
  • 18-20 oz. mahi-mahi or other firm white fish
  • 4-5 large radishes trimmed and thinly sliced
  • 3 tbsp fresh cilantro leaves chopped
  • 8 8- inch corn or gluten-free tortillas


  • Combine the ingredients for the Blackened seasoning in a small bowl and stir to combine. Set aside.
  • To prepare the coleslaw, add the sliced cabbage, kale leaves (if using), and shredded carrot to a large, non-reactive bowl. Whisk the Greek yogurt, apple cider vinegar, ground cumin, Dijon mustard, and lime juice together in a smaller bowl and pour over top of the other vegetables. Season with salt and black pepper, to taste, and toss to combine. Set aside.
  • Generously season both sides of the mahi-mahi with the blackened seasoning and rub to cover the entire fish and to make sure it adheres well. Carefully slice the fish into bite-sized pieces and set aside. Note: You can slice the fish before seasoning, but it takes longer to coat each piece individually and the blackened flavor will be much stronger if all sides are coated.
  • Add the olive oil to a large cast-iron or other skillet over medium heat. Once heated, add the seasoned fish and cook until opaque and flakey, approximately 3-4 minutes per side. Remove from heat and set aside.
  • To serve, evenly divide the creamy coleslaw and blackened fish between the 8 tortillas. Top with the sliced radishes and fresh cilantro leaves. If desired, drizzle some Creamy Avocado Sauce on top. Enjoy!  


You can make these low-carb by choosing low-carb tortillas instead of gluten free. 


Calories: 322kcal | Carbohydrates: 28g | Protein: 32g | Fat: 11g | Saturated Fat: 2g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 6g | Cholesterol: 65mg | Sodium: 1363mg | Potassium: 1048mg | Fiber: 10g | Sugar: 10g | Vitamin A: 4743IU | Vitamin C: 102mg | Calcium: 179mg | Iron: 4mg

Use Your Keto Taco Spice Mix In These Recipes


Make Your Own Avocado Cream Sauce

  • 1 c. plain whole-milk Greek yogurt
  • 1 medium avocado, peeled and chopped
  • 2 cloves garlic, peeled and finely minced|
  • 1 t. ground cumin
  • ½ t. smoked paprika
  • ½ t. chili powder
  • 2 T. fresh cilantro, finely chopped
  • 3 T. fresh lime juice*
  • Sea salt and black pepper, to taste

Place all ingredients in a food processor and blend until smooth. (*Add additional lime juice, if necessary, to reach desired consistency). Taste and adjust seasonings, to taste.
Serve immediately or store in an airtight container in the refrigerator for several days. Enjoy! 

On and Off Keto | + posts

Iva discovered the keto diet back in 2020 and has experimented with it, off and on. She recently took over this site and shares experiences, her knowledge and some yummy recipes. She also runs a women only website Women Blazing Trails.

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