Sweet Potato and Tinned Tuna Fishcakes — Gut-Friendly Recipe
Fibre, protein and resistant starch in one soft, easy-to-digest fishcake — a simple way to nourish your gut microbiome every day.
Ingredients
- 400 g sweet potato (about 2 medium potatoes, weighed raw with skin on)
- 2 tins of tuna in spring water (about 280 g drained)
- 2 eggs
- 3 tablespoons finely blended rolled oats (or rice flour for a gluten-free version)
- 2 tablespoons fresh chives, finely chopped (or spring onion greens)
- 1 tablespoon fresh flat-leaf parsley, finely chopped
- 1 teaspoon ground cumin
- Zest of half a lemon (optional, if tolerated)
- Salt and mild black pepper, to taste
- 1–2 tablespoons extra virgin olive oil (for cooking)
Instructions
Preparation Steps
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Steam the sweet potato: Peel the sweet potatoes and cut them into roughly 3 cm cubes. Steam for 15–20 minutes, until tender and easily pierced with a fork. Steaming preserves water-soluble micronutrients — such as potassium and beta-carotene — better than boiling.
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Leave to cool: Spread the cooked cubes out on a plate or chopping board and leave to cool at room temperature for at least 10 minutes, longer if time allows. This cooling process encourages the formation of resistant starch, which acts as a natural prebiotic for your beneficial gut bacteria.
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Mash the sweet potato: Using a fork, roughly mash the cooled cubes. Aim for a slightly chunky texture rather than a completely smooth purée — this helps the fishcakes hold their shape and better preserves the fibre structure.
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Prepare the tuna: Drain the tuna thoroughly, pressing the tins firmly to remove any excess water. Flake it finely with a fork into a large mixing bowl. This step also helps reduce excess sodium.
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Combine the mixture: Add the mashed sweet potato, beaten eggs, oats (or rice flour), chives, parsley, cumin, and lemon zest (if using) to the bowl. Mix well with a fork or by hand until you have a uniform, mouldable mixture. If it feels too wet, add an extra tablespoon of oats; if too dry, a few drops of olive oil will do the trick. Season with salt and pepper to taste.
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Shape the fishcakes: Divide the mixture into 8 equal portions. Shape each one into a round cake about 1.5 cm thick, pressing firmly between your palms. Slightly damp hands make shaping easier. Place the fishcakes on a plate and refrigerate for 5–10 minutes if possible — this rest firms them up and reduces the risk of them falling apart during cooking.
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Cook the fishcakes: Choose whichever method suits you best:
- On the hob: Heat the olive oil over a medium heat in a non-stick frying pan. Add the fishcakes without crowding the pan. Cook for 4–5 minutes on each side, until golden and firm to the touch. Avoid moving them too soon to prevent breaking.
- In the oven: Preheat to 200 °C (fan). Arrange the fishcakes on a baking tray lined with baking paper, brush lightly with olive oil, and bake for 20–25 minutes, turning halfway through. This method is slightly gentler on digestion as it requires less fat and produces fewer compounds associated with frying.
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Serve: Plate the warm fishcakes alongside a simple green salad (rocket, lamb's lettuce, or cucumber), a few lemon slices, and, if you like, a light dipping sauce made from lactose-free yoghurt mixed with chives and a pinch of cumin. Avoid sauces containing garlic powder, onion, or polyol sweeteners if you are following a low-FODMAP diet.
Gut-Friendly Tips & Adaptations
For sensitive tummies (IBS / irritable bowel)
- Stick to around 70–80 g of sweet potato per fishcake (one serving): beyond this, its polyol content may become fermentable and trigger symptoms in some people.
- Replace part of the sweet potato with cooked carrot or standard white potato, which are better tolerated on a low-FODMAP approach.
- Use rice flour instead of rolled oats if you are sensitive to gluten or oats.
- Avoid adding garlic or onion: chives and spring onion greens deliver the same fresh, aromatic flavour without the irritating FODMAPs.
Resistant starch tip Prepare the sweet potato the day before: cooking it and then leaving it in the fridge overnight maximises the conversion of starch into resistant starch. Reheat the finished fishcakes gently (oven at 160 °C for 10 minutes) to partially preserve this prebiotic effect.
Variations
- Stir in a handful of well-squeezed, finely chopped spinach to boost your fibre and magnesium intake.
- Swap the tuna for tinned salmon for a higher omega-3 content.
- For an egg-free version, use one tablespoon of chia seeds soaked in three tablespoons of water for 10 minutes as a substitute for each egg.
Storage The fishcakes will keep for 2 days in the fridge in an airtight container. They reheat well in a frying pan over a low heat or in the oven. You can also freeze them — raw or cooked — for up to 1 month.