Barbadian Mustard Roasted Fish Steaks
A bright, zesty roasted fish dish inspired by Barbadian coastal cooking. Thick fish steaks (mahi-mahi, swordfish, or kingfish) are coated in a peppery mustard crust infused with turmeric, garlic, and fresh thyme, then roasted until the flesh is tender and flakes easily. The mustard chars slightly at the edges while the fish stays moist inside. Serve with lime wedges and roasted vegetables for an island-inspired dinner.
Steps
Before you start
- Preheat oven to 425°F (220°C) with a baking sheet inside
- Pat fish steaks dry with paper towels—moisture on the surface will prevent proper browning
- Measure out all seasonings before you start
Mix the mustard crust
- In a small bowl, whisk together the Dijon mustard, whole grain mustard, olive oil, minced garlic, turmeric, and fresh thyme.
- Season with a pinch of sea salt and black pepper.
- The mixture should be thick and paste-like, clinging to a spoon.
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Ready when: Mixture is well combined and paste-like
Tip: Don't skip whisking—it emulsifies the mustard and oil so the coating spreads evenly
Coat the fish steaks
- Place the dry fish steaks on the hot baking sheet.
- Generously spread the mustard mixture over the top of each steak, dividing it evenly among all four.
- Coat about half an inch down the sides, leaving the bottom uncoated so it makes contact with the hot sheet.
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Ready when: Each steak is well coated on top and sides
Tip: Using a hot baking sheet means the fish sears on contact, preventing it from sticking
Roast the fishOven 425°F / 220°C
- Place the baking sheet in the preheated 425°F (220°C) oven.
- Roast for 15–18 minutes, depending on the thickness of your steaks.
- Fish is done when it flakes easily with a fork at the thickest part and the internal temperature reaches 145°F (63°C).
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Ready when: Flesh flakes easily; internal temperature is 145°F (63°C); mustard edges are golden-brown and slightly charred
Tip: Don't flip the steaks—the direct heat on the bottom creates a light crust while the top stays moist
Rest and serve
- Remove the baking sheet from the oven and let the fish rest for 2–3 minutes before plating.
- Transfer each steak to a warm plate, scraping any pan drippings over the top.
- Serve immediately with lime wedges and roasted vegetables.
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Ready when: Fish is plated and ready to eat
Tip: Squeezing fresh lime over the fish brightens the mustard crust and adds authentic island flavor
Good to know
Tips
- Fish steaks have bones and skin that add flavor; don't remove them before cooking. They're easy to push aside on the plate after roasting
- For crispier mustard edges, brush a thin second coat of mustard on top halfway through cooking
- Pair with seasoned rice, roasted sweet potato, and wilted callaloo or spinach for an authentic Barbadian meal
- The mustard crust acts as a flavor barrier, keeping the fish moist inside while building a savory, slightly charred exterior
Storage & reheating
Leftover roasted fish steaks keep, covered, in the refrigerator for up to 2 days. Reheat gently in a 300°F (150°C) oven for 8–10 minutes, covered with foil, until heated through. Do not reheat in the microwave, as it will dry out the fish. Best eaten fresh the same day.
Substitutions
- Dijon mustard → whole grain mustard only (use 4 tablespoons / 60 ml total). Gives a more rustic, seeded texture; slightly less sharp flavor
- fresh thyme → dried thyme (1 teaspoon / 1 g). Use one-third the amount; dried herbs are more concentrated. Add it to the mustard mixture and let sit for 5 minutes so the thyme rehydrates
- fish steaks (mahi-mahi, swordfish, or kingfish) → 1-inch (2.5 cm) thick white fish fillets (halibut, cod, snapper). Reduce roasting time to 12–14 minutes for thinner fillets; check doneness more frequently
- extra-virgin olive oil → melted coconut oil. Adds subtle tropical flavor authentic to Barbadian cooking; use the same amount
