recipe developer . podcast co-host . cookbook author . photographer . mental health warrior . online educator


food . travel . life

keto . low carb


gluten-free . grain-free . sugar-free

drama-free . dogma-free . mean-free

TOday's most popular POSTS

Keto Cookbooks


Copyright © Carrie Brown 2010-2024, unless otherwise stated. All rights reserved.

Mushroom Tuna Melt

Hello!  I am writing this on a Saturday.  It will be posted on a Sunday.  What day of the week is it now that you are reading it?  I have no clue.  And more to the point, it doesn’t matter in the slightest.  Food is not day-specific.  We love that.  Another thing we love is a Mushroom Tuna Melt.

Tuna Melt is one of those strange American things that I never really understood until I had been stateside for a while.  We don’t have Tuna Melts in England.  Well maybe we do now (anyone??), but we certainly didn’t when I was living there.  Thinking about it, we’re really not huge tuna (pronounced “chew-na”) eaters in England; we’re way more into salmon.  Americans, on the other hand, just loooooooove their tuna (pronounced “too-na”).  They get all excited about the difference between the albacore and the chunk light; we Brits didn’t even know there was such a thing as albacore.  Alba what??  I remember the first time I saw the dizzying array of canned tuna choices in a US grocery store.  Heavens to Betsy!  I just want a can of tuna, people.

Another thing that was a mystery to me when I arrived on this side of the pond was Portobello mushrooms.  I don’t remember ever having heard of them in England.  Portobello is the name of the world’s largest antiques market, and it’s in London.  That’s all I know.  Once I got to the good ol’ USA, however, I started seeing the word “Portobello”  on menus and hearing people talk about it; to be honest I could never quite figure out what they were on about.  Then one day I saw some ginormous Portobello mushrooms at the grocery store, and I knew I had to introduce myself.

I decided, in a random moment of “Let’s do something different!”, to marry a Portobello mushroom with a tuna melt, which after some cruising around the internet I discovered is essentially a tuna salad with melted cheese sandwich.  Or something very close to that.

Mushroom Tuna Melt |

I grilled (broiled) a huge old Portobello mushroom, melted some cheese on it, and then, when it came bubbling and sizzling out of the oven, heaped tuna salad on top.  It was fun, fast and fabulous.  It was also delicious.  I’ll be doing it again.

I love this dish: fish, Greek yogurt and veggies – and really more assembly than cooking.  Hurrah!  I do love meals that don’t require more than assembly for my own dinners. Because recipe development takes ages.  Another thing that would make a lot of you happy is that you can make a large batch of the tuna salad in advance and then just grill (broil) up your Portobello and cheese in 5 minutes when you get home for a super-fast, keto supper.  I took the rest of the tuna salad as lunch the next day, along with a Romaine lettuce.  Lunch splendidness right there waiting in the ‘fridge as I headed out the door in the morning.  Love that.

I love how all the textures work in this Mushroom Tuna Melt – creamy dressing, silky melted cheese and crisp, crunchy veggies; all topping a sturdy, substantial super-‘shroom.  I ate mine out on the terrace in the dwindling Spring sunshine.  It was quite lovely.

I have now completely embraced both Tuna Salad and Portobello mushrooms.  Twelve years late, but I got there eventually.

Please don’t wait that long before you try this Mushroom Tuna Melt!


Mushroom Tuna Melt

Author: Carrie Brown | Prep time: 5 mins | Cook time: 8 mins | Total time: 13 mins | Serves: 2

What You Need

  • Coconut oil spray or avocado oil spray
  • 2 large Portobello mushrooms
  • 3 oz / 85g strong cheddar cheese, grated
  • 7 oz. / 200g canned tuna
  • 1 large stick celery, finely sliced
  • ½ English cucumber, sliced and then quartered
  • 4 TBSP unsweetened full fat Greek yogurt
  • ½ TBSP lemon juice
  • 1 TBSP white wine vinegar
  • Sea salt and pepper
  • ½ tsp guar gum

What You Do

  1. Spray a baking sheet with coconut oil, place Portobello mushrooms upside down on the sheet and grill (broil) for about 6 minutes until tender.
  2. Meanwhile, in a bowl mix the tuna, celery, cucumber, Greek yogurt, lemon juice, white wine vinegar, and salt together well.
  3. Sprinkle the guar gum evenly over the tuna salad and quickly mix immediately to incorporate it into the salad thoroughly.
  4. Spread the grated cheese evenly over the mushrooms and place back under the heat to melt the cheese, about 2 minutes.
  5. When the cheese is completely melted, remove the baking sheet from the oven.
  6. Carefully transfer each mushroom onto a separate plate.
  7. Pile tuna salad onto each mushroom.
  8. Grind some black pepper over and serve.


Top Recipe Tips


Helpful Cooking and Recipe Links


Podcast Episodes


Mushroom Tuna Melt |






Add a comment...

Your email is never published or shared. Required fields are marked *

  • SusieSounds delish Carrie!!!
    Two questions; where did you find coconut oil spray and did you use a 12 ounce can of tuna?

    • carrieHi Susie! Coconut Oil is readily available in US grocery stores. Since Trader Joe’s have recently introduced their own brand, I am now using that. I used a small can of tuna, but you could certainly double it if you wanted to up the protein. Hope that helps!ReplyCancel

  • SusanMade today for lunch. We don’t eat much cheese, but being a holiday we splurged. Didn’t have guar gum so didn’t use as we make tuna salad frequently with yogurt for lunch…usually over a big bunch of greens.

    Loved the mushroom/cheese turna melt! Thank you.

    • carrieWOW, Susan – that was fast!!! I added guar gum as the yogurt tends to run with the warmth from the cooked mushroom, which wouldn’t happen with your usual greens, but if you found it went ok without then YAY! So glad you loved it!! :-)ReplyCancel

  • SusanCarrie – I had everything already so it was easy peasy! Keep them coming.ReplyCancel

  • SaharaWe also tried this tonight (because it was fresh in my mind and I forgot to prep/marinate the chicken that was planned). So grateful for a quick and easy option. I also did not use the guar gum – because I didn’t have any and it worked just fine without it.
    DH loved it – didn’t even notice the lack of mayo; DD – liked it but found it a bit too tangy; I thought it was just right. I never thought I’d be okay w/o the mayo, but the vinegar and lemon juice added just the right amount of zing for me. Thanks!ReplyCancel

    • carrieSahara – different yogurts may work slightly different, so glad it worked out without the gum for you! So happy too, that you, DH, and DD all enjoyed it :-)ReplyCancel

  • PhilippaWell that sorts lunch for tomorrow.

    And to update you on England, we do have tuna melt (but it probably started in Starbucks), we now have Portobello mushrooms (at least M&S does) and canned tuna is beginning to get a bit more exotic – but I haven’t noticed albacore.ReplyCancel

  • Mushroom Pizza Bites » Carrie Brown | Living a SANE Life[…] fest.  It wasn’t intentional when I started out, but after I had so much fun with the Mushroom Tuna Melt, every time I saw a mushroom I wanted to stuff it with something. Those Portobellos with Tuna […]ReplyCancel

  • LouiseI love to get recipiesReplyCancel

  • WrenVery good! Just a little too salty for my taste so next time I’ll make it without the salt and only 2 oz of cheese. Once I put all the ingredients in MyFitnessPal, it turned out quite high in fat with 3 oz of cheese. My tuna was from Wild Planet and it had some sea salt in it already so that was probably the reason for the extra saltiness. Other than that it’s definitely one to save and make again and again.ReplyCancel

    • carrieWren – glad you loved it. We are not afraid of healthy fats. “Eat as much cheese as you need to stay happy” – J. Bailor :-)ReplyCancel

  • JanetTuna was too sour. I will leave out the vinegar next time. Otherwise it was good.ReplyCancel