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One Pan Blackened Mahi Mahi and Roasted Vegetables

One pan blackened mahi mahi is a great way to take dinner from boring to healthy and filling. With less than 10 carbs per serving, the delicate flavor of this fish and your favorite vegetables comes to the to the table in less than 30 minutes.

Low carb | Gluten free | Grain free | Dairy free

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a skillet of blackened mahi mahi with roasted sweet potatoes and broccolini

What does Mahi Mahi taste like?

Mahi Mahi is firm and mild. Some people say it has a slightly sweet taste–maybe it does–but it’s not much of one. Nowhere near the flavor of salmon or tuna, this fish is the perfect place to introduce seafood to picky eaters because it’s not obviously fishy. The meat is firm when cooked but juicy and flakes easily with a fork.

As the mother of two children who don’t like fish, this is the only one they will occasionally agree to eat in fish tacos. That’s still a win to me.

I read that Mahi Mahi is dolphin. Is that right?

Don’t worry. You’re not eating dolphin. Mahi mahi is the Hawaiian name for the species of fish called Coryphaena hippurus. In Spanish it’s called the Dorado or the dolphin fish in English. It’s not the air-breathing mammal. Mahi Mahi are most often found in the Gulf of Mexico, Costa Rica and Hawaii and are sustainably fished.

Is Mahi Mahi healthy?

Mahi mahi is a good source of lean protein, is high in niacin and B12, phosphorous and selenium and has about 400mg of omega-3’s per 4 ounce serving. The fish fillets you see pictured in this recipe were about 4 ounces each–that’s about 1″ thick and about 3 inches long or about the size of your palm.

Tips for the best blackened fish and vegetables

6 steps to blackened mahi mahi broccolini, potatoes, seasoning, mahi mahi and broccolini and potatoes in a skillet
  1. Use whatever green vegetable you like. I tried broccoli rabe (broccolini) here and we HATED it. It’s super bitter and literally no one gave that a thumbs up. Instead, I’d recommend using asparagus or fresh broccoli that you’ve sliced in to thinner spears. Both would cook in the same amount of time.
  2. Pre-cook your potatoes (I used sweet potatoes here) in the microwave until they are just fork tender. You can use baby red potatoes as well, but you’ll want them mostly cooked before adding them to the skillet. You could even do this a couple of days ahead and leave the cold potatoes whole in the fridge until you needed to dice them.
  3. Use a skillet that goes from stove top to oven. Of course cast iron is what I’m using and will always recommend.
  4. Make sure your fish is fully thawed and patted dry. Coat the fish on both sides well with the seasoning and when you put it in the pan, don’t move it for two to three minutes so it will “blacken”.
a skillet of blackened mahi mahi with roasted sweet potatoes and broccolini

One Pan Blackened Mahi Mahi and Roasted Vegetables

A little spicy, and a lot flavorful this blackened mahi mahi makes an easy dinner.
Prep Time 10 minutes
Cook Time 17 minutes
Servings 3 people
Author Rachel Ballard


  • cast iron skillet


  • 12 ounces mahi mahi thawed and patted dry
  • 12-15 spears broccolini, broccoli or broccoli rabe *see note 1
  • 1 large white sweet potato about 1 1/2 cups diced *see note 2
  • 3 tablespoons avocado oil divided
  • 1 tablespoon butter
  • 1/2 teaspoon salt
  • lemon wedges

For the blackened seasoning

  • 1/4 teaspoon cayenne pepper
  • 1/2 teaspoon dried thyme
  • 1/2 teaspoon smoked paprika
  • 1/4 teaspoon garlic powder
  • 1/4 teaspoon onion powder
  • 1/2 teaspoon salt
  • 1/4 teaspoon black pepper


  • Preheat the oven to 425.
  • Scrub the skin of the sweet potato and microwave it until just starting to get tender. About 2 to 2 1/2 minutes. When cool enough to handle, dice into 1/2" pieces, leaving the skin on. Set aside.
  • Trim the broccolini, broccoli or broccoli rabe into even size pieces. Cut away any large leaves and trim stalks to about 2 inches long. If the stalks are thick, cut them in half down the length so they cook more evenly. Wash if needed and set aside.
  • Mix the cayenne, thyme, paprika, garlic powder, onion powder, salt and pepper together in a small bowl. Pat the fish fillets dry well with paper towels and sprinkle both sides of the fish evenly with the seasoning.
  • In a 12-inch cast iron or oven proof skillet, heat 2 tablespoons of avocado oil over medium high 2 to 3 minutes. Add the fish and allow it to sit 2 to 3 minutes on the first side before turning. Cook 1 minute on the second side and move the fish to a plate. It will not be cooked through and that's okay.
  • Add the butter and remaining tablespoon of avocado oil to the hot pan, reduce heat to medium and add the broccolini and sweet potato. Toss to coat and cook until just starting to pick up some color off the bottom of the pan–about 4 minutes.
  • Add the fish back into the skillet and transfer it all to the oven. Bake 10 minutes.
  • To serve, add a bit more butter if desired, and a sprinkle of salt. Squeeze over lemon and serve warm.


Note 1: We didn’t love the broccolini/broccoli rabe. Instead I’d suggest using fresh broccoli spears, leaving about 2 inches of the stalk and cutting them thinly or using asparagus you’ve cut in to two three inch pieces. 
Note 2: You can use regular potatoes here if you choose. Just pre-cook them in the microwave until just tender before adding them to the skillet. You can also pre cook your potatoes, leave them whole and store in your fridge to dice for this recipe when you’re ready to cook. 


Calories: 296kcalCarbohydrates: 10gProtein: 22gFat: 19gSaturated Fat: 4gCholesterol: 93mgSodium: 934mgPotassium: 618mgFiber: 1gSugar: 2gVitamin A: 6773IUVitamin C: 5mgCalcium: 30mgIron: 2mg
Tried this recipe?Tag us on Instagram @feastandfarm and hashtag it #feastandfarm
Course Main Course
Cuisine American

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  1. A little known tip when it comes to Broccoli Rabe/Broccolini is to blanch before cooking. Restaurants would serve it and it was delicious at home always bitter. Then I found a recipe online that blanched it and it made a big difference.

  2. If I don’t have a cast iron do you recommend I cook on top in a pan and transfer to an oven sheet? Or can I skip cooktop and place everything in the oven?

  3. 5 stars
    My husband loved this dish. I used asparagus and yellow sweet potatoes because that is what I had on hand. Will definitely make it again.

  4. Two questions: #1: is avocado oil specifically necessary to the flavour of this dish? Can I substitute a different oil – I am allergic to avocado 🙁

    #2: On a scale of 0-10, how spicy would you say this is, with the cayenne pepper? (I am a wuss)

    1. Hey Bonnita, No the avocado is just what I use for high heat cooking because I don’t use vegetable oil (It’s not so good for you). You can use any other good high-heat tolerant oil. And as for spicy…I’d call it a 3 or a 4. Feel free to leave the cayenne out. 🙂 –Rachel

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About the Author

Rachel Ballard, RN, BSN brings more than 20 years of professional nursing expertise to Feast and Farm. With a love for nutrient dense foods that support wellness, she works to distill complex health information and current trends into recipes that fuel the best version of yourself. Read more about Rachel here.