I have been trying to incorporate a bit more fish into my diet lately. I struggle with good low FODMAP protein options and fish fits the bill perfectly. What better way to serve fish than in low FODMAP fish tacos?
These low FODMAP fish tacos are low in fuss and deliver on taste. They take into account the FODMAP content of various ingredients normally used in tacos to ensure everything remains above board.
The tacos use fish that is coated in spices (and a small amount of optional rice flour) before being pan fried in a hot non-stick pan.
A simple lettuce, pickled jalapeño and coriander slaw forms the vegetable base. This easy low FODMAP mix adds pop of colour, flavour and freshness, but also keeps the FODMAP content in check.
Our tacos are topped with pickled jalapeño, a lactose free crema, low FODMAP pickled red onion and extra coriander. A big squeeze of lime is all that’s needed to finish these delicious and fresh low FODMAP fish tacos.
Balancing FODMAPs
It’s important to go through the FODMAP containing ingredients in these tacos to ensure everything remains within acceptable limits. I will go through substitution options in the section below if you’re looking to adjust any FODMAP content.
These thresholds are current as of August 2026 and will be periodically updated to ensure they remain accurate.
Firstly, we have corn tortillas. Corn tortillas are low FODMAP in up to 133g serves per person (5 1/2 tortillas) if they contain gums and added fibres. In larger serves, they contain moderate amounts of fructans.
If they do not contain gums or fibre, they are low FODMAP in up to 425g (20 tortilla) serves. In larger serves, they contain moderate amounts of fructans.
Blue corn tortillas are low FODMAP in up to 370g serves. In larger serves, they contain moderate GOS and fructans.
Lime juice is another fructan containing ingredient. It is low FODMAP in serves of up to 279g which is approximately 1 cup. This is far more lime juice than we’re using but it still worth discussing, given the tortillas.
Pickled red onion is low FODMAP in up to 85g serves. In larger serves, it contains moderate amounts of fructans.
Korean chilli powder is low FODMAP in up to 5g serves per person. In larger serves, it contains moderate fructose.
Smoked paprika is low FODMAP in up to 5g serves per person. In larger serves, it contains moderate fructose.
Why lettuce?
Fish tacos traditionally use a purple or white (or both) cabbage slaw. Cabbage does have a low FODMAP threshold but it is a fructan containing ingredient in serves over 194g (white common cabbage) or 162g (red cabbage).
Because we’re already getting fructan from the corn tortillas, pickled onion and lime juice, adding cabbage takes it too far in the fructan direction (which I found out the hard way).
So, while lettuce isn’t necessarily traditional, it is a delicious and low FODMAP way to make these fish tacos flexible.
I used Cos/Romaine lettuce in my photos because I like the texture and it is the lowest FODMAP lettuce that contains fructose. Cos/Romaine lettuce is low FODMAP in 75g serves. It contains moderate amounts of fructose in serves exceeding 182g. This recipe uses 200g lettuce, so this should remain under the fructose threshold.
Interestingly, Iceberg lettuce is a fructan containing ingredient. Even though you can eat a lot before it comes an issue (488g, to be precise) I decided not to use it here.
Keeping the fructan content down
Fructan is the main FODMAP to be aware of in this recipe. Tortillas, lime juice and pickled onion all contain fructan. This is of note for people like me who know that fructan is their arch nemesis in the FODMAP world.
There are plenty of options for those who are hyper intolerant to fructan, though. First of all, make your own gluten free tortillas. My recipe is gum free and uses white rice flour and tapioca flour, so it’s a good corn free option either way. If you can’t have rice flour, you can also use my buckwheat wraps, quinoa wraps or teff wraps (although they will add a new flavour).
If you make them, I would recommend cutting the homemade tortillas into 14cm circles (5.5 inches). This is the size of corn tortillas sold in Australia. This will ensure the ratios of fish to lettuce to sauce aren’t thrown off.
Interestingly, Monash lists hard corn shell tacos as being low FODMAP in up to 500g. Although I feel that fish tacos are best with soft shells, this is another option.
Next, you can omit the pickled red onion. I think this is huge in adding classic flavour so I would recommend exploring the tortilla options instead.
What sort of fish should I use?
The most common sorts of white fish differ from country to country. If you’re not based in Australia, I recommend looking up the best white fish for tacos where you live. If you go to a fishmonger, they should also be able to help you choose.
I have tested Flake, Rockling and Barramundi and all worked well. My personal favourites were the Rockling and Barramundi.
Other firm white fish in Australia includes Snapper, John Dory, Blue Eye Trevalla and Flathead.
I haven’t tested salmon, trout or any rich and oily fish varieties here. I don’t think they would work well personally.
Adding spiciness on the low FODMAP diet
A lot of heat giving ingredients (looking at you, dried chillies) contain moderate amounts of fructose in small serves. If you malabsorb fructose and love spicy foods, this can be a bit of a dilemma. I have a few tips on adding extra spice on the low FODMAP diet for those of who miss the heat.
- Use lots of freshly cracked black pepper, which brings a peppery heat.
- Prioritise hot dried chillies over mild ones. Korean chilli flakes are very mild (which is why I love them). If you want a lot of heat, use cayenne pepper to your tastes. It is low FODMAP in 2g (1 teaspoon) serves, but doesn’t contain moderate fructose until it exceeds serves of 10g (1 tablespoon).
- If you want to build the heat according to everyone’s preferences, pickled jalapeños are here to save the day. They remain low FODMAP in serves of up to 500g per person, which makes them a great way to customise the heat level for everyone.
More low FODMAP gluten free recipes
- Low FODMAP baked fish parcels
- Low FODMAP Pad Thai (vegetarian/vegan option)
- Low FODMAP vegan bolognese
- Low FODMAP peanut tofu bowls
- Low FODMAP falafel bowls
Low FODMAP fish tacos
Ingredients
For the fish:
- 700-750 g firm white skinless fish I tested Rockling, flake and Barramundi
- 1 teaspoon fine table salt
- 3 teaspoons cumin powder
- 1 teaspoon smoked paprika
- 1 teaspoon Korean chilli flakes or regular chilli flakes, to your tastes – see notes
- 1 teaspoon dried Mexican or regular dried oregano
- Pinch of asafoetida powder optional, see notes
- 2-4 teaspoons fresh and fine white rice flour optional, see notes
For the lettuce mix:
- 200 g Cos/Romaine lettuce finely chopped
- ¾ bunch coriander finely chopped (remainder used for garnish)
- Chopped pickled jalapenos to your tastes
- Squeeze of lime juice
- Lime zest to your tastes
- Seasoning to your tastes
For the crema:
- 200 g lactose free sour cream
- lime juice to taste
- 1-2 pickled garlic cloves grated (see notes)
- Drop of liquid smoke optional
To finish:
- 40-80 ml (2-4 tablespoons)* neutral oil, for cooking the fish
- Pickled red onion see notes
- Extra pickled jalapenos to your tastes
- Lime wedges and lime zest to your tastes
- 12 small corn or gluten free tortillas see notes
- Remaining coriander to serve
Instructions
- Combine the seasoning mix in a small bowl. Liberally coat the fish in the dry seasoning mixture and set aside.
- Combine the ingredients for the lettuce mixture in a large bowl and season according to your tastes. Make sure you chop the lettuce finely so it isn’t too large or pokey to fit in small tacos. Massage the seasoning into the lettuce slightly to soften it, then set aside.
- Combine the ingredients for the crema sauce in a medium bowl. Adjust according to your preferences and set aside.
- Heat a large non-stick pan very thoroughly over a medium heat. Once it is thoroughly heated, add 1-2 tablespoons of neutral oil and 2-3 fillets of fish. Cooking them in two batches (if necessary) ensures they don’t get too soggy in the pan.
- Cooking time depends on the size you are using and the width of the fillets. 8-10 minutes is ideal timing for thick fillets of Rockling.
- Turn the fish incrementally to ensure it is evenly cooked through. Remove from the pan and repeat with the remaining fillets, washing the pan first if necessary.
- Once the fish is cooked, take it off the heat. I find Rockling benefits from 5-10 minutes to drain off any excess liquid.
- Use two forks to flake the fish into large chunks. You can heat it through gently if it needs it.
- Heat your tortillas and assemble your fish tacos – crema, lettuce mix, fish, ½ – 1 tablespoon of pickled red onion, extra coriander and extra jalapeno if you like.
- Leftover fish keeps in an airtight container in the fridge for 3-4 days.
Notes
- See the body of the post for extensive FODMAP notes.
- I use Korean chilli flakes which have a beautiful red colour and less heat than regular chilli flakes. If you use regular chilli flakes, use them to your tastes.
- Note that they do contain fructose, so I recommend capping the chilli at 1 teaspoon and adding extra pickled jalapeno to your taco if you like extra heat (they are low FODMAP in serves of up to 500g). You can also look into cayenne chilli powder which has a slightly higher FODMAP threshold.
- Asafoetida powder is a low FODMAP alternative to garlic and onion powder. It is optional, but does add a nice depth of flavour. A little goes a long way so I recommend only a pinch.
- Note that some asafoetida powder is cut with wheat flour, so check the label if you are catering to a coeliac.
- White rice flour is optional but does add a little crispiness and helps soak up a bit of liquid. Make sure it’s finely milled and fresh (not the stuff in the box) so it doesn’t ruin the texture of the fish.
- If you have spices leftover from the fish, sprinkle it over as it cooks or after baking. This still applies if you used the rice flour option, so it’s super important to use a fine and fresh rice flour to avoid aforementioned texture issues.
- Pickled garlic is low FODMAP in 3g serves and up to 29g. It is an optional ingredient to add an extra layer of flavour to the crema (but it still tastes good without). I have a recipe for pickled garlic here.
- Pickled red onion is low FODMAP in serves of up to 85g. Monash hasn’t specified but I assume that this only applies to properly pickled onion as opposed to quick pickled onion. I have a recipe for low FODMAP pickled onion on my website.
- Use my recipe for gluten free tortillas for a lower FODMAP alternative to corn tortillas. I used the recipe to make twenty three 14cm tortillas (5.5 inches).
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