Tuna was something that I recently learned how to eat. You see, I never liked fish. Not smoked salmon, not sushi, not even fish sticks. That changed about two years ago. I had been on the low FODMAP diet for a while and wanted to expand my range of recipes. And that’s how I ended up with a bunch of tuna cans. This low FODMAP lemon fish cakes recipe is the second thing I tried to make (and eat) and is still one of my favorites. The tuna taste isn’t very present and the lemon brightens the whole dish.
It’s a fairly greasy dish, being fried and then dipped into mayonnaise. Fatty foods can be a trigger for IBS symptoms, so be careful if that’s the case for you. You could swap the regular mayonnaise for a low-fat version.
Ingredients for low FODMAP lemon fish cakes
These are the most important ingredients for your fish cakes, with some pointers from my side (but scroll on to the recipe for the full ingredient list).
Canned tuna in water – Plain tuna. Using tuna in oil also works, but the mixture will need more gluten-free flour to stop it from sticking to your hands.
Floury potatoes – Semi-floury also works, as long as it mashes well.
Lemon – As you’re going to zest it, use an unwaxed lemon. According to the Monash app, lemon juice contains fructans. This recipe stays well under the safe serving of 125 grams of lemon juice. The zest only contains trace amounts.
Gluten-free all-purpose flour – I used Schär Mix It! Universal. You’ll use this to make a firmer mixture, and keep the fish cakes from falling apart.
Spring onion – Only use the green parts of the spring onion; these are low FODMAP and give an onion-like flavour.
Instant polenta – Also known as corn semolina, the uncooked polenta is used to get a crispy ‘breaded’ crust. Gluten-free breadcrumbs exist but it was harder to find, more expensive, and didn’t give the same level of crispiness.
Sunflower oil – This neutral-tasting oil is great for frying. Rapeseed oil is a good alternative.
Lamb’s lettuce – My go-to lettuce. You could use other soft-leaf lettuces like butter lettuce or coral lettuce. All three of these contain no FODMAPs.
Make ahead & freeze
Usually, I’ll double the recipe and freeze half of my low FODMAP lemon fish cakes. These make a perfect freezer meal! After step 6 (so before frying), line a tray with parchment paper and put them in the freezer for three hours. When they’re frozen solid, transfer them to an air-tight container. Make sure no frost develops on the fishcakes; this will make them soggy when thawed.
To prepare your frozen fish cakes, let them thaw in the fridge overnight. Then you can fry them as usual.
Low FODMAP lemon fish cakes
- 150 grams canned tuna
- 300 grams floury potatoes
- 1 lemon, unwaxed
- 1 medium egg
- 1 stalk spring onions, green party only
- 3 tbsp gluten free all-purpose flour
- 80 grams lamb's lettuce (or another soft leaf lettuce type)
- 1/4 tsp table salt
- 1/4 tsp ground black pepper
- 50 grams instant polenta
- 3 tbsp sunflower oil
- 50 grams mayonnaise
- 1/4 lemon, for garnishing, optional
- Wash and dry the lettuce and divide over two plates.
- Peel and dice the potatoes. Boil in a pot with salted water for 15-20 minutes, or until soft. Then drain and let it rest (without a lid on the pot) for a couple of minutes.
- Mash the potatoes. Drain the tuna and add it to the potatoes. Use a fork to tear the tuna into small flakes. Beat the egg and add pour it in as well.
- Slice the spring onion into thing strips. Zest the lemon and squeeze the juice from one half. Add this to the potato mixture along with the gluten free flour, green onion, salt and pepper. Stir the mixture until all ingredients are mixed in completely.
- Put the uncooked instant polenta into a bowl or on a plate. Use your hands to form patties from the fish cake paste, then coat it with the polenta. If the fish cakes stick to your hands at this point or fall apart as you coat them, add extra gluten free flour to the paste.
- Set a large skillet on the stove on medium high heat. When the skillet is properly hot, add two tablespoons of sunflower oil. Fry the fishcakes for five minutes on each side, or until they start to colour. Add more oil for frying if needed.
- Put the mayonnaise into a small bowl. Squeeze juice from the leftover lemon half and use two tablespoons of lemon juice for the mayonnaise. Stir until combined. Set aside.
- Place the fish cakes on top of the lettuce and serve with your lemon mayonnaise.
- Lemon juice is low FODMAP up to 125 grams per serving (after that, high in fructans).
- Plain mayonnaise and canned tuna shouldn’t have added FODMAP ingredients, but it’s best to check before you start cooking.
Blogpost and recipe last revisited August 2022.