Review: Shake Shack x Fortnum and Mason

The Christmas season is well and truly here, the lights are twinkling, the yule logs are baking, and the Christmas songs have started playing.

Even fast food joints aren’t immune to the infectiousness of the festive season. Shake Shack on Cornmarket Street has launched its Christmas menu, which is more indulgent than usual. Offering festive twists on all its new classics, and brand new drink flavours, it might be worth popping in to treat yourself.

One caveat to point out straight away is that the Christmas menu at Shake Shack heavily relies on the flavour of white truffle, so if you are not a fan of truffle then this may not be the menu for you. I personally love truffle, so was excited to give this a go. I tried the white truffle burger, which was a cheeseburger topped with white truffle sauce, crispy shallots served on a toasted potato bun. It was decent for a fast-food style burger, but I found it lacking in the truffle sauce. I also like my burger buns to have some integrity, and I found the Shake Shack bun to be a bit soft and mushy. For the price, £11.45 for a single and £14.25 for a double, it felt like quite a high cost. I felt like I could get a much better burger for the same price elsewhere.

Thankfully, they did not skim on the truffle sauce for the other items; their signature crinkle cut chips were lathered in the stuff and coated in parmesan too, they were probably my favourite thing from the Christmas menu.

Potato, truffle and cheese is always going to be a winning combo. The Christmas onion rings were the same as off the normal menu but came with a little pot of truffle sauce for you to dip into. I appreciated the sauce coming on the side as then you could control how much you wanted and also use it for your other items, if needed. I am never a huge fan of onion rings, but actually the ones at Shake Shack were not too greasy or too battered, so was pleasantly surprised. Again, nothing overly special but you got a decent portion size.

The most unique part of the Christmas menu was the new drinks that were a result of a partnership with Fortnum & Mason. They had a new shake flavour – the Merrilossus Shake.

It tasted like a mix between vanilla and chocolate, I had never really tasted something like that before. It was made with Fortnum & Mason biscuit milk tea and cranberry purée topped with whipped cream and crushed Merrilossus biscuits. It was far from the best shake I have had, I personally found it a bit too sweet with not a lot of depth of flavours and it tasted a little on the artificial side. But I kept sipping it throughout my meal, so it keeps you going back for more.

Then there was the cranberry tea fifty/fifty which was an iced drink of cranberry lemonade with spiced Fortnum & Mason Christmas Tea. This one was much more refreshing and paired well with the indulgent truffle items.

We also tried a few items off their usual menu to see how they fared and the crispy shallot burger went down very well, it was tangy and rich and coming in at £9.55, much more reasonable in price too. The cheese fries were extremely more-ish, I usually am not a fan of cheese sauces as they never really taste like cheese to me and are always an unhealthy colour of orange. But the cheese sauce at Shake Shack actually tasted a bit cheesy which made it more enjoyable than I was expecting.

I also tried the chicken bites with BBQ sauce, and they are exactly what you would expect and similar to chicken bites at a lot of fast food restaurants, although at over £1 per bite, it felt like a slightly high price for mediocre food. If you are a fan of Shake Shack and you enjoy the flavour of truffle then this Christmas menu will be right up your street. If you have a sweet tooth then you will also love the new Fortnum & Mason drinks they have on offer, so make sure you pop in before the 6th of January 2026 to give them a go.