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Steak and Onion Sandwich

Steak and Onion Sandwich

Steak and onion

There is nothing better than a steak and onion sandwich. It is quick and easy and fills a hole.

This steak and onion sandwich recipe is actually a steak sandwich recipe with caramelised onions, as it is just superior!

caramelised onion


Many years ago when I worked in London, I would occasionally pick one of these up at the local deli.

They would be made with delicious fresh bread and were delicious. The combination of the steak, the sweetness of the caramelised onions and the bitterness of the mustard is just a classic taste.

My best steak sandwich!

open steak sandwich

One of the tricks is to find a nice bread to make your sandwich with. A nice sourdough loaf would do nicely, but I did not have one to hand for this one.

An Italian ciabatta or even a nice French baguette – what could be better than a steak sub?!


best barbeque food


The other key trick is to caramelise the onions to perfection. You could of course just use fried onions for this, but it is not quite the same.

Caramelising the onions, as described below,  gives that extra special taste that combines so well with the mustard and steak.

flank steak sandwich

Steak cut

And of course, the right cut of meat is essential. You need to have a cut that is tender and not chewy.

I have used some delicious sirloin in these photos. I can get this very cheaply at my local supermarket (Aldi) and it is from Black Angus bulls and has been 30 day aged. It is tender and very tasty.

So when you are wondering what to take to a BBQ, with a nice piece of steak and some tasty bread you can hardly go wrong.

You can produce a BBQ steak sandwich in no time, as long as you have somewhere to cook the onions.


sirloin steak sandwich

Steak and Onion Sandwich


You can of course also always add some rocket leaves or something similar to make it more colourful if you wish.

grilled steak recipe


I hope you enjoy making your own steak and onion sandwich. Let me know how you get on in the comments section below!

How to make a steak and onion sandwich

steak and onion sandwich

Steak and Onion Sandwich

Prep Time: 5 minutes
Cook Time: 15 minutes
Total Time: 20 minutes

This steak and onion sandwich will have you begging for more. The caramelised onions combine perfectly with the mustard and steak to make a delicious snack!


  • 450g steak (I have used 30 day aged Black Angus sirloin from Aldi)
  • 2 onions, peeled
  • 1 tbsp Olive oil
  • 20g salted butter
  • 45g demerara sugar
  • 100ml red wine vinegar
  • Tasty bread
  • Dijon mustard


  1. Let the steak acclimatise to the room temperature before you start (30 minutes or so outside the fridge).
  2. Slice the onions into 1cm thick circular pieces.
  3. Melt the butter, sugar and oil in a pan and add the onions and fry for about 5 minutes.
  4. Then add the vinegar, put a lid on the pan and cook on a low heat for about 10-15 minutes until the onions have caramelised.
  5. Meanwhile tenderise the meat by placing between some baking sheets and carefully hammering with a roller pin.
  6. Then season the steak on both sides with salt and pepper. Then fry the steak in some olive oil in a pan on a high heat.
  7. Cook the steak for about 3-4 minutes each side, depending how well you want it done (and on the thickness of the steaks).
  8. When cooked to your preference (check by slicing off a piece), remove to a plate. 
  9. Then prepare whichever bread you have organised. I used a simple seeded Vienna loaf and fried both sides in a bit of olive oil. I then dipped in some of the meat’s resting juices, and added some mustard. You could also use some ciabatta or any other tasty piece of bread.
  10. After resting the meat for a minute or so slice into pieces to fit your bread.
  11. Load your sandwich with the meat, onion and mustard as required, and dig in.


On a plate with napkins and a pint of beer.

Nutrition Information:
Yield: 2 Serving Size: 1
Amount Per Serving: Calories: 935Total Fat: 57gSaturated Fat: 23gTrans Fat: 0gUnsaturated Fat: 27gCholesterol: 240mgSodium: 327mgCarbohydrates: 40gFiber: 2gSugar: 28gProtein: 62g

This nutrition information was automatically calculated by Nutritionix, but may not be 100% accurate.

Did you make this recipe?

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If you enjoyed this recipe, then please check out some of my other recipes in this link: recipe index.

Or these:

Steak and ale pie with mushrooms
Chicken Curry Sandwich
Chicken Mayo Sandwich
Shredded Beef Sandwiches (Instant Pot)
Gluten Free Crispy Onions
Pulled Pork With Coke
Apple Cranberry Coleslaw
Steak Diane Recipe
Braised steak and onions in slow cooker

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