Save to Pinterest Sink your teeth into this vibrant Australian fusion creation, where perfectly grilled barramundi fillets meet the smoky sweetness of charred cos lettuce. The star of the show is undoubtedly the grilled lemon jalapeño tartare—a zesty, creamy condiment that brings brightness and just the right amount of heat.
The grilling process transforms humble ingredients into something extraordinary. Barramundi's naturally sweet, buttery flesh develops gorgeous char marks while remaining incredibly moist. The cos lettuce leaves, briefly kissed by flame, add a subtle smokiness that perfectly complements the fresh seafood.
Assembly is straightforward: marinate your fish, grill the lemons and jalapeños for the sauce, char the lettuce alongside the fillets, then layer everything between toasted brioche buns. The result is a harmonious blend of textures—crisp lettuce, flaky fish, soft bun—and flavors that dance between smoky, zesty, creamy, and fresh.
The summer my brother-in-law brought his portable BBQ to our beach holiday changed everything about how I think about fish burgers. We were skeptical about grilling barramundi outside, especially with the wind threatening to flip our carefully planned dinner into the sand, but that first bite of char-grilled fish with smoky lettuce made us all go quiet. There is something magical about how the grill transforms ordinary ingredients into something that tastes like a coastal restaurant meal. Now every time I fire up the barbecue, I think of that breezy evening and the way the tartare sauce brought everything together.
I made these for a neighborhood gathering last summer, and my neighbor Sarah actually asked if I had hidden culinary training. She could not believe that the secret was simply grilling the lemon halves and jalapeños first, which concentrates their flavors in ways that fresh ingredients never achieve. The kids were skeptical about fish burgers but ended up asking for seconds, their faces covered in that zesty tartare sauce. There is nothing quite like watching people discover that fish can be the star of a burger.
Ingredients
- Barramundi fillets: This mild Australian fish is perfect for grilling because it holds its shape beautifully and takes on marinade flavors like a dream. Any firm white fish will work if you cannot find barramundi at your local market.
- Grilled cos lettuce: Brushing romaine with olive oil and throwing it on the grill might seem unusual but it creates this wonderful smoky sweetness that balances the rich fish.
- Lemon and jalapeños: Grilling these first transforms them entirely. The lemon becomes sweeter and more complex while the jalapeños lose some harsh heat and gain a smoky undertone.
- Good-quality mayonnaise: Since this tartare is so simple, use the best mayonnaise you can find. Homemade would be next level but a premium store-bought version works perfectly.
- Brioche buns: The slight sweetness and sturdy structure of brioche holds up to the juicy fish and generous tartare without falling apart.
Instructions
- Marinate the fish:
- Whisk together olive oil, lemon zest, minced garlic, salt, and pepper in a shallow dish. Coat the barramundi fillets and let them sit for 10 minutes while you prep everything else.
- Fire up the grill:
- Get your BBQ or grill pan to medium-high heat. You want it hot enough to create nice char marks but not so aggressive that the fish sticks and falls apart.
- Grill the aromatics first:
- Place lemon halves cut-side down and jalapeño halves on the grill. Let them cook for 3 to 4 minutes until they are nicely charred and softened, then remove and set aside to cool slightly.
- Make the magic sauce:
- Finely chop those grilled jalapeños and squeeze about 2 tablespoons of juice from the charred lemons. Mix them with mayonnaise, capers, dill, parsley, diced shallot, Dijon mustard, salt, and pepper.
- Grill everything else:
- Cook the barramundi for 3 to 4 minutes per side until just cooked through. Brush the cos lettuce with olive oil and grill for 1 to 2 minutes per side until slightly wilted. Lightly toast the buns on the grill too.
- Build your masterpiece:
- Spread that tartare generously on both bun halves. Layer on grilled lettuce, a piece of barramundi, tomato slices, and cucumber if you are using it. Top with the bun and devour immediately.
Save to Pinterest These burgers have become our summer staple, the meal everyone requests when we have people over. There is something about the combination of smoky grilled elements and that bright zesty tartare that makes people pause mid-bite and ask what exactly makes them so good. I love standing at the grill, tongs in hand, watching the fish and lettuce char to perfection while everyone gathers around, drinks in hand, waiting for dinner.
Making It Ahead
The tartare sauce actually gets better if you make it a few hours ahead, letting those grilled jalapeño and lemon flavors meld together. Keep it chilled and give it a good stir before assembling. You can also marinate the fish earlier in the day but do not add the salt until right before grilling or it might affect the texture.
Perfect Pairings
A crisp white wine like Australian Sauvignon Blanc cuts through the richness beautifully, or go with a cold pale ale if you prefer beer. A simple potato salad with a vinegar-based dressing balances the meal, or some grilled corn on the cob with lime butter would be fantastic alongside.
Scaling For A Crowd
When I cook these for a big group, I set up a station with all the components and let people build their own burgers. The grilled lettuce tends to cool down quickly, so grill it in batches right before serving. Extra tartare is never a bad idea because guests always want more for their fries or bread.
- Keep the toasted buns warm in a low oven while you finish grilling the fish
- Have extra lemon wedges on hand for those who love extra acidity
- Set out extra napkins because these can get wonderfully messy
Save to Pinterest Every time I serve these burgers, I think about that beach holiday and how a simple grilled fish dinner turned into one of our most requested meals. Hope your family loves them as much as mine does.
Recipe FAQs
- → What makes barramundi ideal for burgers?
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Barramundi's firm, meaty texture holds up beautifully on the grill and won't fall apart when you take a bite. Its naturally sweet, buttery flavor pairs perfectly with the smoky grilled elements and zesty tartare sauce.
- → Can I prepare the lemon jalapeño tartare ahead?
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Absolutely. The tartare sauce actually benefits from sitting for 30 minutes to an hour, allowing the flavors to meld together. Store it in the refrigerator and give it a good stir before assembling.
- → What's the purpose of grilling the lemon halves?
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Grilling lemons caramelizes their natural sugars, creating a sweeter, more complex juice. The charred flavor adds depth to the tartare sauce that fresh lemon juice simply can't achieve.
- → How do I know when the barramundi is cooked?
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The flesh should turn opaque and flake easily with a fork. Barramundi is best served just cooked through—about 3-4 minutes per side depending on thickness. Overcooking will dry out this naturally moist fish.
- → Can I cook this indoors without a BBQ?
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Yes, a grill pan or even a heavy skillet works well. You won't get quite the same smoky flavor, but you can add a pinch of smoked paprika to the fish marinade to compensate.
- → What other fish can I use?
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Firm white fish like snapper, cod, mahi-mahi, or halibut work beautifully. Avoid delicate fish like sole or tilapia as they'll break apart during grilling and assembly.
