How to Cook Costco’s Frozen Mahi Mahi for a Healthy and Delicious Meal!

Costco is selling a three pound bag of frozen mahi mahi filets from the Kirkland Signature brand. The filets are boneless, skinless and individually vacuum packed.

The mahi mahi filets are wild caught and a product of Ecuador.

Kirkland Mahi Mahi at Costco

I have been eating these filets twice a week and am very satisfied with the quality of the fish.

This is the fish that I bought at my local Costco.  Costco has a similar product for sale on its website but that is wild caught Pacific mahi mahi and is a product of Taiwan.  I believe the products should be very similar but I have not tried the fish from Taiwan.

Mahi Mahi Poached in Marinara

Costco Mahi Mahi Poached in Marinara

Costco's frozen Mahi Mahi filets are thawed, seasoned and then poached in marinara sauce before being served over cauliflower rice.
Prep Time 10 minutes
Cook Time 7 minutes
Total Time 17 minutes
Course Main Course
Cuisine American
Calories 195 kcal


  • 1 filet Costco Mahi Mahi per person
  • 1 cup Rao's Marinara Sauce
  • 2 tsp Salt per filet
  • 2 tsp Black Pepper per filet


  • Thaw the frozen mahi mahi filets in their packaging either overnight in the refrigerator or in cold running water in the sink.
  • Remove the filets from the wrapper, rinse with cold water and pat dry with paper towels.
  • Season both sides of the fish with salt and pepper.
  • Pour one cup of Rao's marinara sauce into a skillet.
  • Place the mahi mahi filets on top of the marinara and cover the skillet with a tight fitting lid.
  • Heat the covered skillet over Medium heat for 5-7 minutes until an internal temperature of 140F is reached.
  • Serve the fish and sauce over a bed of steamed cauliflower rice or with a side of steamed veggies.
Keyword Costco Mahi Mahi


You get three pounds of individual filets per bag.  One serving is a four ounce portion of fish and there are about 12 servings in the bag.

Mahi Mahi Nutrition

The nutritional facts for a single serving are:

  • Calories: 100
  • Fat: 1g (1% DV)
  • Cholesterol: 80mg (27% DV)
  • Sodium: 100mg (4% DV)
  • Carbohydrates: 0g (0% DV)
  • Protein: 21g

At first I thought that each filet was a 100 calorie serving but when I broke out the scale and started weighing the portions I was surprised to find that many of the filets weighed 8 ounces or more.

This means that some filets are equal to two servings and have about 200 calories.

Mahi Mahi portion size


Cooking Instructions

Mahi mahi is a versatile fish that can be cooked several ways (grilled, baked, poached, air fryer).

Regardless of how you end up cooking it the first step is to remove however many filets you want and let them thaw in the refrigerator.  he packaging says it should take between 8-10 hours for the fish to thaw but I have found that 24 hours is more likely.

You can “fast thaw” the filets under cold running water but this is not recommended.

Do not cook the fish from a frozen state.

Individual portions of Mahi Mahi

Once the filets are thawed I like to rinse them with cold water and pat dry with paper towels.

Season the filets as desired and cook to an internal temperature of 140F.

One of my favorite ways of cooking mahi mahi is to season both sides with a little salt and pepper and then gently poach the fish in Rao’s marinara with a closed lid for about 5-7 minutes.

I serve the mahi mahi and marinara over some seasoned cauliflower rice and it is a delicious and filling meal.


Mahi mahi is a whitefish with a very mild fish flavor.  It does not have the oily, fatty texture of salmon.  The meat is dense, firm and does not want to flake and fall apart.

I tend to think of mahi mahi as a much firmer version of cod.

The mild flavor makes mahi mahi a great choice for people who “don’t like fish”.  The firm, meaty texture makes mahi mahi great for making tacos or sandwiches.  I much prefer making a sandwiches from a grilled mahi mahi filet than from one of the mahi mahi burgers from Trader Joe’s.

Mahi Mahi Poached in Marinara

Costco Value

You can by the three pound bag of mahi mahi at Costco for $22.99 which comes out to a cost of $7.63 per pound.

For comparison:

  • The frozen Atlantic Cod filet portions cost $8.25 per pound. 
  • The frozen Pacific Salmon filet portions cost $14.95 per pound. 

This makes the mahi mahi some of the least expensive frozen fish available at Costco.

Price of Frozen Mahi Mahi at Costco



Good morning and welcome to the site dedicated to helping you find great products at Costco and other stores! My name is David Somerville and these are hands on reviews of products that I have bought and used or am seriously considering purchasing. I do most of my shopping at the Costco in Baton Rouge, Louisiana but will check out any other Costco warehouses I find while travelling. Please get in touch with any questions and let me know of any great products that deserved to be featured in this blog!

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