Save to Pinterest Sink your teeth into this vibrant Australian fusion creation where perfectly grilled barramundi meets 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 together the brightness of charred lemons, the gentle heat of grilled jalapeños, and the briny pop of capers.
The fish gets a simple yet effective marinade of olive oil, lemon zest, and garlic before hitting the grill, ensuring each fillet develops those beautiful charred marks while remaining incredibly moist and flaky inside. Grilling the cos lettuce might seem unusual, but it transforms the crunchy leaves into something beautifully smoky and slightly wilted—the perfect textural contrast to the tender fish.
Assembly is straightforward: toast your buns, slather on that homemade tartare, layer up the grilled components, and finish with fresh tomato slices for a burst of sweetness. The whole dish comes together in just 40 minutes, making it impressive enough for entertaining but simple enough for a weeknight dinner.
The first time my mate Tom brought barramundi back from a fishing trip up north, he grilled it whole on a beach barbecue with nothing but salt and lemon. We ate it standing up, with paper plates, watching the sunset, and Ive been chasing that flavor ever since. This burger is my way of bringing that Australian beachside memory into everyday life, minus the sand in your shoes.
Last summer I made these for a Sunday afternoon gathering and my sisterinlaw literally scraped every drop of tartare sauce off her plate with a fork. She still texts me about that sauce. Theres something about the combination of fresh fish, warm grilled lettuce, and that spicy kick that makes people forget they are eating burgers at all.
Ingredients
- Barramundi fillets: This Australian native has a beautiful buttery texture that holds up perfectly on the grill, though snapper or cod work beautifully too
- Olive oil: Use a good quality one here since it forms the base of your fish marinade
- Lemon: Youll grill half the lemon for an incredible charred citrus flavor in the tartare and use the zest in the fish marinade
- Jalapeños: Grilling them tames the heat just enough while adding this gorgeous smoky depth
- Mayonnaise: Spend the extra money on a quality brand here, it makes all the difference in the tartare
- Capers: These little saltbombs cut through the richness and add those bright pops of brine
- Fresh dill and parsley: The herbs bring this beautiful freshness that balances all the grilled flavors
- Cos lettuce: Grilling romaine transforms it into something entirely different, sweet and smoky
- Brioche buns: Their slight sweetness and soft crumb are perfect for holding everything together without falling apart
Instructions
- Get your grill going:
- Fire up your barbecue or grill pan to mediumhigh heat, letting it get nice and hot so you get those beautiful char marks on everything
- Marinate the fish:
- Whisk together olive oil, lemon zest, garlic, salt and pepper, then coat your barramundi fillets and let them sit for about 10 minutes while you prep everything else
- Prep the lettuce:
- Separate your cos lettuce into large leaves and give them a light brush with olive oil so they grill up beautifully instead of drying out
- Make the magic tartare:
- Grill your lemon halves cut side down and jalapeños for 3 to 4 minutes until charred and soft, then finely chop those jalapeños and squeeze out 2 tablespoons of that incredible grilled lemon juice
- Stir it all together:
- Mix your mayo, grilled jalapeños, lemon juice, capers, herbs, shallot, Dijon mustard, salt and pepper, then pop it in the fridge to let those flavors hang out together
- Grill the fish:
- Cook those marinated barramundi fillets for 3 to 4 minutes per side until just cooked through and lightly charred, being careful not to overcook them
- Char the lettuce:
- Throw those cos leaves on the grill for just 1 to 2 minutes per side until slightly wilted with gorgeous grill marks
- Toast your buns:
- Give your brioche buns a quick toast on the grill so they are warm and slightly crispy, perfect for holding all those juicy components
- Build your masterpiece:
- Spread that grilled lemon jalapeño tartare on both bun halves, then layer up grilled cos lettuce, your beautiful barramundi fillet, tomato and cucumber slices
- Serve them up:
- Get these burgers into peoples hands immediately while everything is still warm and that fish is perfectly flaky
Save to Pinterest These burgers have become my go to when I want to impress without actually trying that hard. Something about grilling the lettuce makes it feel fancy, but really you are just throwing vegetables on a hot barbecue and hoping for the best.
Making It Your Own
If you cannot find barramundi, any firm white fish will work beautifully. The key is choosing something that will not fall apart on the grill. I have made this with snapper when I could not get my hands on barramundi, and honestly, it was just as good.
The Heat Factor
Some people like it mild, others want to feel it. I usually leave a few seeds in one of the jalapeños, which gives a gentle warmth that builds. If you love serious heat, keep all the seeds or even add an extra jalapeño to the grill.
Perfect Sides
A crisp Australian Sauvignon Blanc cuts through the richness beautifully. For something non alcoholic, a cold sparkling water with extra lime works wonders. I have also served these with simple potato wedges seasoned with rosemary and sea salt.
- Make extra tartare sauce, it keeps for days and is incredible on everything
- Have your brioche buns at room temperature before toasting
- Wipe down your grill between the jalapeños and fish so the flavors do not get muddled
Save to Pinterest Theres nothing quite like standing around the grill with friends, cold drink in hand, watching these come together. Summer food at its finest.
Recipe Q&A
- → Can I use other fish instead of barramundi?
-
Absolutely. Snapper, cod, mahi-mahi, or any firm white fish works beautifully here. Just adjust cooking times slightly based on fillet thickness.
- → How spicy is the jalapeño tartare?
-
Mild to medium. Grilling tames the heat significantly, while the mayonnaise and herbs mellow it further. Leave seeds in if you prefer more kick.
- → Can I make the tartare sauce ahead?
-
Yes, prepare it up to 24 hours in advance and refrigerate. The flavors actually develop and improve overnight.
- → What if I don't have a BBQ?
-
A grill pan or heavy skillet works perfectly. You can also use your oven broiler for the lemons and jalapeños, then pan-sear the fish.
- → Can I grill the lettuce ahead of time?
-
It's best grilled just before assembling, as it wilts quickly. However, you can grill it 10-15 minutes early and keep it at room temperature.
- → What sides pair well with this burger?
-
Crisp beer-battered chips, a fresh Greek salad, or roasted potato wedges with rosemary. An Australian Sauvignon Blanc or pale ale complements beautifully.
