Oven Roasted Mahi Mahi

Those who like seafood will love this easy oven-roasted mahi-mahi recipe. I perfected it to make it in less than 30 minutes with asparagus and juicy roasted tomatoes on the side. I only need two baking pans, so there is minimal clean-up time, too. This is a lean and healthy dinner; its simplicity and fantastic flavors will win you over. 

My family loves fish and seafood, so I often make easy and delicious recipes, such as these popular salmon foil packets – talk about a no-mess recipe, and this oven-roasted Spanish Mackerel, a recipe I learned while living in Spain. I firmly believe that sometimes the best food is simple, with just a few ingredients to highlight and enhance its natural flavors.

I used frozen Mahi-Mahi filets for this recipe, which tend to be cheaper, but fresh fish would be even better. For frozen filets, make sure you let them thaw before cooking. This simple but scrumptious dish is perfect for any night of the week, and I love that the side dish is made simultaneously. Sometimes, I add a salad like my favorite broccoli cauliflower salad with homemade honey lemon dressing. These two dishes seem like they were made for each other.  

Why you will love this recipe 

• It’s fast and easy. Preparing and cooking a delicious meal for the whole family takes less than 30 minutes. 
• Easy cleanup: I also make it all on two baking sheets protected with parchment paper, so cleanup is a breeze.   
• The kids love it even though it’s healthy: This fish is packed with healthy omega-3 fatty acids, lean protein, and plenty of vitamins and minerals, and the kids love all the flavor.
• There is no need for side dishes: Since it has its own side dishes, there is no need to make anything else. 

What you will need

• Mahi-mahi fillets—I cook five fresh or frozen fillets, about six ounces each, for my family. If they are frozen, they need to be thawed and patted dry. 
• Lemons – I use two fresh lemons for lemon juice and freshly grated lemon zest. 
• Garlic cloves—I rub fresh minced garlic cloves into the fish with lemon zest and juice for a bold, garlicky taste. 
• Fresh thyme – For a slightly lemony hint that complements the delicate taste of the mahi-mahi.
• Grape tomatoes – Grape tomatoes are the perfect size to cook whole, so they stay juicy when cooked in the oven with the fish. They add a pop of color and a burst of flavor.
• Fresh thin asparagus—I serve the asparagus on the side, coated with olive oil and lemon juice and seasoned with salt and pepper. 
• Crumbled feta – The creamy and salty feta cheese gives the slightly sweet asparagus a delicious contrast and complex flavor profile. 

How to make 

Preheat and prepare: First, I preheat the oven to 400 degrees F, line the bottom of two baking sheets with oiled parchment paper, and place the fillets on one. Then, I brush the fillets with olive oil, season with salt and pepper, rub in the garlic and lemon zest, and squeeze the juice of one lemon over them.

Prep the tomatoes: I then toss the grape tomatoes in one teaspoon of olive oil and a pinch of salt and pepper.

Bake: I add the tomatoes to the pan with the fish. Then, I top the fish with fresh thyme and bake for 10 to 15 minutes or until it is opaque in the center. 

Prep the asparagus: In the meantime, I prepare the asparagus by cutting off the woody ends and placing them on the other prepared baking sheet. I drizzle them with olive oil and the juice of half a lemon and season them with salt and pepper before tossing them to coat. 

Rest and serve: I let the asparagus cook for 10 to 15 minutes. Then, I remove the thyme sprigs from the fish and serve everything with crumbled feta on top and extra lemons on the side. 

Expert tip

How to find the freshest mahi-mahi

To get the freshest, I usually visit my local fish market. If possible, I always choose wild-caught fish, as it is healthier and tastes better. Mahi-mahi should be fresh, moist, and have a nice vibrant color with bright, clear eyes. The flesh should be translucent pink, and it will have a visible red bloodline. It should not be soft or mushy. The smell will be mild and fresh but never fishy or like ammonia. If in doubt, buy frozen fish instead. 

More tips to consider

• Let frozen fillets thaw in advance so they are ready when needed. Then, squeeze out any excess water with paper towels.
• Rinse fresh fillets before using them and pat them dry with paper towels. 
• Zest the lemons when they are whole. Then, cut them in half for juicing. 
• Do not overcook the fish. Only cook it until it is just opaque in the center. 
• Watch out for bones. Even if it is supposed to be boneless, they can miss some. 

Recipe variations and add-ins:

• Different fish: Although mahi-mahi is the key ingredient here, if it is hard to find, other choices are whitefish, halibut, tilapia, and cod.
• Italian mahi: I love adding seasonings to my fish because it is so easy to absorb flavors. My homemade Italian seasoning tastes incredible when rubbed into this fish and goes well with the lemon and asparagus.
• Cajun fish: For a spicier kick, using one teaspoon of Cajun seasoning is another savory way to enjoy this dish. 
• More vegetables: Sometimes, I add more vegetables, such as broccoli florets, bell peppers, celery, and green beans, to make this a heartier dish. 
• Add potatoes: Another way to make this dish heartier is to chop some baby red potatoes and add them to the asparagus. Just ensure they are small and you start roasting them 15 minutes before you add the asparagus and the fish, as they take longer to cook.

Serving suggestions:

This seafood dish is a fast way to feed the family on busy weeknights when I don’t have much time. It pairs well with fluffy white rice or a hearty side dish like this slow cooker rice and beans recipe. My low-carb cauliflower rice is delicious for those trying to cut their carb intake, as is my roasted cauliflower steak.

I often pair it with a quick dessert, like my no-bake lemon cheesecake, which I can make in advance. For something simple yet still delicious, try my tropical fruit salad. Pinot Noir also pairs well with this fish. The wine’s acidity cuts through the fish’s oiliness nicely.

How to store leftovers:

• Refrigerate: Leftovers should be refrigerated in an airtight container and will stay fresh for up to three days.  
• Freezing: Freezing is not recommended.  
• Reheating: Reheat leftovers in the oven at 375 degrees F for 10 minutes. 

Frequently asked questions

More fish dinners to try: