Grilled Mahi-Mahi Foil Packets with Lime and Cilantro

Quick Recipe Version (TL;DR)

• Yield: 4 servings
• Prep Time: 20 minutes
• Cook Time: 12–15 minutes
• Total Time: 35 minutes

Quick Ingredients

• 4 mahi-mahi fillets (5–6 oz each, about 1 inch thick)
• 2 bell peppers (mixed colors), thinly sliced
• 1 small red onion, thinly sliced
• 3 limes (zest of 2, juice of 3) + extra lime wedges
• 1/3 cup fresh cilantro, chopped
• 4 cloves garlic, minced
• 3 tbsp olive oil
• 2 tbsp unsalted butter, melted (optional but delicious)
• 1 tsp ground cumin
• 1/2 tsp smoked paprika
• 1/2 tsp chili powder (optional, for mild heat)
• 1 1/2 tsp kosher salt, divided
• 1/2 tsp freshly ground black pepper
• Heavy-duty aluminum foil

Do This

• 1. Preheat grill to medium-high heat (400–425°F). Cut 4 large sheets of heavy-duty foil, about 16 x 18 inches.
• 2. In a bowl, whisk lime zest, lime juice, olive oil, melted butter, garlic, cumin, smoked paprika, chili powder, 1/2 tsp salt, and black pepper.
• 3. Toss sliced bell peppers and red onion with 3 tbsp of the lime mixture; divide evenly in the center of each foil sheet.
• 4. Pat mahi-mahi dry, season both sides with remaining 1 tsp salt, and place one fillet on top of each vegetable mound. Spoon remaining lime mixture over fish. Sprinkle with half the cilantro.
• 5. Fold foil into tightly sealed packets, leaving a little space inside for steam.
• 6. Grill packets, closed, for 12–15 minutes, turning once halfway, until fish flakes easily with a fork.
• 7. Carefully open packets (watch for hot steam), top with remaining cilantro and lime wedges, and serve immediately.

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Why You’ll Love This Recipe

• Everything cooks together in foil packets, so cleanup is fast and easy.
• The mahi-mahi steams gently in lime, cilantro, and peppers for a bright, flaky finish.
• Foolproof for the grill: the foil protects the fish from sticking or drying out.
• Flexible and healthy: easy to adapt with extra veggies or different levels of spice.

Grocery List

• Produce: 4 limes, 2 bell peppers (any colors), 1 small red onion, 1 small zucchini (optional), 1 bunch fresh cilantro, 4 cloves garlic
• Dairy: Unsalted butter (or use extra olive oil if you prefer dairy-free)
• Pantry: 4 mahi-mahi fillets, olive oil, kosher salt, black pepper, ground cumin, smoked paprika, chili powder, heavy-duty aluminum foil

Full Ingredients

For the Lime-Cilantro Marinade

• Zest of 2 limes (about 2 tsp packed zest)
• Juice of 3 limes (about 6 tbsp), divided as needed
• 3 tbsp olive oil
• 2 tbsp unsalted butter, melted (or substitute 2 tbsp additional olive oil)
• 4 cloves garlic, minced
• 1 tsp ground cumin
• 1/2 tsp smoked paprika
• 1/2 tsp chili powder (optional, for gentle heat)
• 1/2 tsp kosher salt
• 1/2 tsp freshly ground black pepper

For the Fish and Vegetables

• 4 mahi-mahi fillets, 5–6 oz each, about 1 inch thick
• 2 bell peppers (red, yellow, or orange), cored and thinly sliced
• 1 small red onion, peeled and thinly sliced
• 1 small zucchini, halved lengthwise and sliced into half-moons (optional)
• 1 tsp kosher salt (for seasoning the fish)
• 1/3 cup fresh cilantro leaves, roughly chopped, divided
• 4 lime rounds or wedges (for placing on top of each fillet, optional)
• Additional lime wedges, for serving
• Heavy-duty aluminum foil (4 sheets, about 16 x 18 inches each)

Step-by-Step Instructions

Step 1: Preheat the grill and prepare the foil

Preheat your grill to medium-high heat, aiming for a temperature of 400–425°F. If using a gas grill, set the burners to medium-high, close the lid, and let it preheat for at least 10 minutes. For a charcoal grill, light the coals and wait until they are covered with gray ash, then spread them in an even layer for medium-high heat.

Tear off 4 large sheets of heavy-duty aluminum foil, each about 16 x 18 inches. If you only have regular foil, use double layers for each packet to prevent tearing. Lightly mist or brush the center of each sheet with a bit of olive oil to help prevent sticking.

Step 2: Make the lime-cilantro marinade

In a medium bowl, whisk together the lime zest, lime juice, olive oil, melted butter, minced garlic, ground cumin, smoked paprika, chili powder (if using), 1/2 teaspoon kosher salt, and black pepper. Whisk until the mixture looks slightly thickened and emulsified. Taste a tiny bit; it should be bright, citrusy, and well-seasoned. If you like more tang, add an extra teaspoon of lime juice.

Set aside about 2 tablespoons of this mixture in a small bowl; you will use it to drizzle over the fish at the end before serving.

Step 3: Season the vegetables

In a large mixing bowl, combine the sliced bell peppers, sliced red onion, and zucchini (if using). Pour most of the remaining lime-cilantro marinade over the vegetables, reserving about 3 tablespoons to brush on the fish. Toss gently until all the vegetables are evenly coated and glistening.

Divide the marinated vegetables evenly among the 4 foil sheets, piling them in the center of each sheet in a rough rectangle slightly smaller than the fish fillets. This vegetable bed will keep the fish lifted off the foil and help it steam gently.

Step 4: Season the mahi-mahi and assemble the packets

Pat the mahi-mahi fillets dry on all sides with paper towels. This helps them cook evenly and absorb the flavors. Sprinkle the fillets all over with the remaining 1 teaspoon kosher salt.

Place one seasoned fillet on top of the vegetables in each packet. Spoon the reserved 3 tablespoons of marinade over the tops of the fillets, dividing it evenly. Sprinkle about half of the chopped cilantro over the fish and vegetables. If you like, place a lime round or wedge on top of each fillet for extra aroma.

To seal each packet, bring the long sides of the foil up and over the fish so the edges meet above the center. Fold the edges together tightly, making a seam, then roll it down several times to seal. Next, fold and crimp the shorter ends tightly toward the center. You want the packets sealed but with a little air space inside so steam can circulate.

Step 5: Grill the foil packets

Place the sealed foil packets on the preheated grill grates, seam side up. Close the grill lid. Cook for 12–15 minutes, turning the packets over once halfway through cooking. Exact time will depend on the thickness of your fillets and how hot your grill runs.

To check for doneness, carefully open one packet (beware of hot steam) and use a fork to gently flake the thickest part of the fish. The mahi-mahi should be opaque and flake easily, with an internal temperature of 130–135°F for moist, tender fish (it will continue to cook slightly off the heat).

Step 6: Finish with fresh cilantro and lime

Use tongs to transfer the packets from the grill to a sheet pan or platter. Let them sit for 1–2 minutes to allow the steam to settle slightly. Then carefully open each packet away from your face and hands, as hot steam will escape.

Drizzle the reserved 2 tablespoons of lime-cilantro mixture over the cooked fish. Sprinkle the remaining chopped cilantro on top. Serve the open packets directly on plates, or slide the fish and vegetables onto warm plates or a serving platter. Add extra lime wedges on the side for squeezing over each serving. Enjoy immediately while the fish is hot and flaky and the peppers are tender-crisp.

Pro Tips

• Use even-thickness fillets: Try to choose mahi-mahi fillets that are about 1 inch thick and similar in size so they cook at the same rate.
• Do not overcook: Fish continues cooking after you remove it from the grill. Pull the packets when the internal temperature is 130–135°F for moist, flaky mahi-mahi.
• Seal packets tightly: Well-sealed packets trap steam, which gently cooks the fish and keeps it juicy. If in doubt, use a double layer of foil.
• Oven option: No grill? Bake the foil packets on a baking sheet at 400°F for 14–16 minutes, then check for flakiness.
• Customize the heat: Add extra chili powder or a pinch of crushed red pepper if you enjoy more spice, or omit the chili powder for a completely mild dish.

Variations

• Spicy chipotle version: Replace the chili powder with 1–2 teaspoons finely chopped chipotle in adobo and add a pinch of cayenne for a smoky, spicy kick.
• Tropical twist: Add 1/2 cup diced fresh pineapple or mango to the vegetable mixture for a sweet-tart contrast to the lime and cilantro.
• Different fish: Substitute halibut, cod, or salmon fillets of similar thickness and adjust cooking time slightly as needed until the fish flakes easily.

Storage & Make-Ahead

This dish is best enjoyed fresh off the grill, when the mahi-mahi is at its flakiest and the peppers are still vibrant. However, leftovers can be stored in an airtight container in the refrigerator for up to 2 days. Let the packets cool slightly, then transfer the fish and vegetables (without the foil) to a container before chilling.

To reheat, place the fish and vegetables in a covered oven-safe dish and warm in a 300°F oven for 10–12 minutes, just until heated through. Avoid microwaving on high, which can make the fish rubbery; if using a microwave, use 50% power and short intervals. For make-ahead prep, you can slice the vegetables and mix the marinade up to 1 day in advance, storing each separately in the refrigerator. Assemble and cook the packets just before grilling for the best texture.

Nutrition (per serving)

Approximate values per serving (1 mahi-mahi fillet with vegetables and sauce): about 360 calories, 36 g protein, 18 g fat, 8 g carbohydrates, 2 g fiber, 3 g sugar, and 530 mg sodium. Actual values will vary based on exact fillet size, amount of sauce consumed, and optional ingredients used.