Tuna Salad with Red Onion
Tuna salad with red onion is a no-cook filling that takes about 20 minutes, including a short rest in the fridge. Tinned tuna is flaked with mayonnaise, lemon juice, dill and finely chopped red onion for a creamy mix with a sharp edge. It makes enough for two generous sandwiches or jacket potatoes, and it works just as well on crackers or piled onto salad leaves.
- Total
- 20 min
- Prep
- 10 min
- Serves
- 2
- Per serving
- 420kcal
Choosing the tuna for tuna salad with red onion
Tuna in spring water gives the cleanest flavour and lets the mayonnaise and lemon do the work. If you only have tuna in sunflower oil, drain it very well. Two 145g cans give about 220g of drained fish, enough for two servings. Raw red onion can take over, so chop it small and add it a little at a time if you are unsure.
Making tuna salad with red onion
Tap a time to start a timer.
- Drain the tuna Open the cans and press the lid or a small sieve against the fish to squeeze out all the liquid. Tip the tuna into a medium bowl.
- Prepare the onion and lemon Peel the red onion and chop it into pieces about 3mm across. If it is very sharp, soak the pieces in cold water for , then drain and pat dry with kitchen paper. Squeeze the lemon to get 1 tablespoon of juice.
- Flake the fish Break the tuna up with a fork until there are no large chunks left, so the salad spreads evenly.
- Mix Add the onion, mayonnaise, lemon juice and dill. Stir until every flake of tuna is coated and the onion is spread through the mix.
- Season Add the pepper and a pinch of salt, stir again and taste. Add a little more lemon juice if it needs brightening.
- Chill Cover and leave in the fridge for so the flavours settle, then serve.
Serving and swaps
Spoon the salad into buttered sandwiches, onto a split jacket potato or over rocket and sliced cucumber. Chopped celery or cucumber adds crunch, and fresh chives can stand in for the dried dill. For a sharper, more savoury version, try tuna salad with capers. The same filling is the starting point for a bagel with tuna salad or a club sandwich with tuna.
Common problems and fixes for Tuna Salad with Red Onion
- The salad is watery.
- Liquid from the tuna or from wet onion thins the mayonnaise. Press the tuna against a sieve until no more liquid comes out, and pat soaked onion dry before mixing.
- The onion overpowers everything else.
- Chop it smaller and soak it in cold water for 5 minutes, as in step 2. This takes the harsh edge off but keeps the crunch.
- The salad tastes flat.
- Add a little more lemon juice or black pepper. Hold back on salt, because tinned tuna and mayonnaise are both salty already.
Frequently asked questions about Tuna Salad with Red Onion
How long does tuna salad with red onion keep in the fridge?
Up to 2 days in an airtight container in the fridge. Stir it before serving, and do not leave it out of the fridge for more than 2 hours. It does not freeze well, because the mayonnaise separates.
What can I use instead of mayonnaise?
Replace half the mayonnaise with Greek yoghurt for a lighter salad, or use all yoghurt with an extra squeeze of lemon and a little Dijon mustard.
How long does it take to make?
About 20 minutes in all: 10 minutes of preparation and 10 minutes in the fridge. Nothing needs cooking.
Can I use fresh tuna instead of tinned?
Yes, but cook it first. Pan-fry a tuna steak until cooked through, let it cool completely, then flake about 220g and mix as above.
How did you like the recipe?
4.8 / 5 · 48 ratings
