Succulent, grilled tuna steak. Perfectly cooked with a little seasoned (seaweed) butter, or other flavoured butters for extra decadence and deliciousness.
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DON’T LOSE THIS RECIPE! PIN Grilled Tuna FOR LATER…

Grilled Tuna Steak and why it makes a great meal
Have you ever made a grilled tuna steak? It’s an absolute favourite treat at GFHQ. Why? Because it’s quick to make and is absolutely delicious. It’s also filling and nutritious and can be dressed up with so many different sauces, marinades and rubs. And… there’s no bones (I HATE bones).

Fresh Grilled Tuna vs Tinned Tuna
No doubt some of you will be wondering why we bother with fresh tuna when we could open a can. And some of you will be thinking ‘but fresh tuna is really expensive’. And sure… We eat tinned tuna here too (mainly on baked potatoes and in sandwiches). But here’s a few reasons why we choose to eat fresh tuna.
Is it really more expensive?
Weight for weight, fresh tuna steak is surprisingly comparable to tinned tuna steak in cost. On the day I checked, a 110g tin of tuna steak in a mid-range supermarket cost £1.20 (£1.09 per 100g). The same supermarket sold 400g fresh frozen tuna steak for £4.60 (£1.15 per 100g). Okay, that excludes supermarket offers and I’m sure prices vary from shop to shop. But there’s really not that much in it.
Fresh tuna steak tastes better
The extra cost is more than worth it for the eating experience you get with fresh grilled tuna. Let’s be honest. Fresh tuna steak and tinned tuna steak are really not in any way comparable, either in how they look or taste.
The canning process gives tinned tuna a slightly powdery, dry texture. Having been cooked at a high temperature before being squashed into tins, it’s hard to imagine it as a fish. Great when mixed with mayonnaise, but totally different to the firm succulence and meatiness that comes from a fresh griddled tuna steak.
Fresh tuna is rich in flavour and firm in texture and transports you to the foodie shores of the Mediterranean and beyond. In addition to steak, it can also be cubed and added to salads, pasta and tray bakes.
Fresh grilled tuna has better nutrition than tinned tuna
Fresh and tinned tuna are both great sources of protein (although fresh is slightly higher), vitamins B12 and selenium. They are also both low in saturated fat. But fresh tuna wins out on its higher levels of omega-3 fatty acids (which help brain function and reduce inflammation). Because tinned tuna gets cooked at high temperatures prior to canning, these essential fatty acids get significantly damaged and reduced.
Whether bought fresh or tinned however, make sure you choose a brand certified by the MSC (Marine Stewardship Council). This will confirm that it has been fished sustainably.

How to cook grilled tuna steak
Fresh tuna steaks are already skinned and boned. So, short of cooking them, there is little prep to be done before they hit the pan. But be aware that tuna cooks really fast and over-cooked tuna will become dry and tough. Keep a close eye to make sure it stays melt-in-the-mouth perfect. And never walk away once it is on the heat.
For pretty ‘lined’ grilled tuna steak, cook it in a griddle pan. My tuna has single lines. But for a criss-cross pattern, simply rotate the tuna a quarter turn part way through cooking.
Brush the tuna (or pan) lightly with a little olive oil to prevent sticking and season with a little salt and pepper (optional). Make sure the pan is VERY hot before laying the tuna down. Depending on steak thickness and how ‘rare’ you want it, cook between 40 and 80 seconds on each side. Just enough to sear and brown the outside and cook part or all way through. I prefer my tuna steaks rare and pink in the middle. But you’ll quickly learn from experience what works for you. If you check the sides as the tuna cooks, you’ll get a good idea of how far through it’s cooked. For a rarer steak, flash-fry and then gently hold the fish with tongs and sear the sides to seal.
The tuna will continue to cook briefly after being taken from the heat, so err ‘under’, rather than ‘over’. And be sure to let it rest for a couple of minutes before serving.

Grilled tuna steak with butter
The possibilities for flavouring and dressing up grilled tuna steak are endless. From simple lemon juice and flavoursome sauces, to using marinades and rubs.
The recipe shared here has been topped with a simple heart of home-made seaweed butter. Easy home-churned butter infused with Seaweed Dulse that I found from Shore at the Allergy and Free From Show. Having checked the Shore website, they don’t seem to sell the small pots that are in the photos anymore. But I found a similar product of Mara seaweed dulse flakes on Amazon. Actually, we use them on loads of things… from sprinkling on fish and over pasta to popping in sauces and seasoning tray bakes.
Don’t want to make butter from scratch? Then grab a pack of your favourite commercial brand, soften slightly and mash through the dulse, or alternatively some minced garlic, herbs or spices.
Or, grilled tuna steak works equally well with commercially flavoured butters that you can find in supermarkets and farm shops. If you are dairy free, you can still enjoy tuna with butter. Either flavour your usual DF brand, or I can recommend Our Paula’s vegan Butta (which comes in sea salt, garlic or chilli flavours).

What to serve with grilled tuna
Grilled tuna should be allowed to shine. Serve with simple accompaniments. A green salad, some simple steamed green veg and some new boiled or Hasselback potatoes are perfect.
Of course, you can also use fresh tuna in other dishes too. Using fresh tuna in a Nicoise Salad will take it to another level. Or combine it with asparagus, baby corn and a little cream for a divine Creamy Tuna Pasta with Asparagus.
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Grilled Tuna Steak with Flavoured Butter
Key equipment
- small bowl
- fork
- hob
- griddle pan
- kitchen tongs
Ingredients
- 4 fresh tuna steaks (or frozen & defrosted)
- ¾ tbsp olive oil
- salt and pepper to taste
- 30 g butter (approx weight) home-made or bought
- ¾ tsp Dulse seaweed flakes (or some herbs/paprika/spice)
Instructions
Flavoured Butter
- Using a fork, mash in the seaweed Dulse, herbs or spices into slightly softened butter.
- When evenly seasoned, shape and chill in a block.
- If making shapes of butter, slice and cut into shapes with a small cookie cutter once firm.
- Keep the cut butter shapes in the fridge until ready to use.
Cook the tuna
- Brush the tuna (or the pan) lightly with a little olive oil to prevent sticking and season with a little salt and pepper (optional).
- Heat the pan on the hob, making sure it is VERY hot before laying the tuna down.
- Depending on the thickness of the steaks and how ‘rare’ you want them, grill in the pan for between about 40 seconds and just over a minute on each side. Just enough to sear and colour the outside and cook part or all way through.
- Check the sides as the tuna cooks, to get a good idea of how far through the fish has cooked. For a rarer steak, flash-fry and then gently hold the fish with tongs and sear the sides to seal.
- Be aware that the tuna will continue to cook briefly after being taken from the heat, so err ‘under’, rather than ‘over’ cooked.
- Let the tuna steaks rest for a couple of minutes before serving.
Notes
Nutrition
© 2019-2023 Kate Dowse All Rights Reserved – Do not copy or re-publish this recipe or any part of this recipe on any other blog, on social media or in a publication without the express permission of Gluten Free Alchemist
Grilled Tuna Steak shared with :
- Cook Blog Share with Apply To Face Blog
- Fiesta Friday #346 with Angie and The Not So Creative Cook
- What’s For Dinner #280 with The Lazy Gastronome
- Full Plate Thursday #503 with Miz Helen’s Country Cottage
Love this, its just totally different, especially the addition of seaweed butter – totally next level stuff!
Thank you so much Chloe.
There’s nothing I love more than ‘playing’ with food xx
The seaweed butter sounds awesome! It could be on any sea fish!! Pinning! Thanks for sharing at the What’s for Dinner party! Hope to see you back tomorrow.
Thanks Helen.
Absolutely. Seaweed and fish in general are made for each other xx
I have literally just been on a bit of a buying spree at an online Japanese food and have lots of packets of dried seaweed that I was wondering how to use. I think your recipe has given me some inspiration for supper this weekend!
Oh wow! Pleased to hear I have impeccable timing.
I hope you enjoy/enjoyed your supper xx
I once had fresh tuna and it was an absolute taste sensation but I have never had it again because I am unsure how to cook it so this recipe is one I’m pinning for using in my own kitchen. You make it sound so easy! Your seaweed butter is inspired! Thank you for sharing it with #CookBlogShare
Thanks Jenny.
I hope I have encouraged you to try cooking tuna at home. It is a regular on the menu here. We use it in so many ways. In fact, Miss GF refuses to eat tinned tuna since there is no comparison! xx
I love the sound of seaweed butter, all those lovely salty sea flavours. I can just imagine how wonderful that is going to be with fresh tuna. Great recipe, I’m bookmarking it for later.
Thank you Janice. The seaweed butter worked perfectly with the tuna. It was such a treat to eat x
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Thank you for sharing at #OverTheMoon. Pinned and shared. Have a lovely week. I hope to see you at next week’s party too! Please stay safe and healthy. Come party with us at Over The Moon! Catapult your content Over The Moon! @marilyn_lesniak @EclecticRedBarn
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Thank you so much Marilyn. And thank you for hosting. You have a great week too x