Mushroom, Caramelized Onion & Cheddar Burgers

Mushroom, Cheddar & Caramelized Onion Burger | (Cooking for) Kiwi & Bean

So I had planned to share a nice warm and stewy fall recipe today, the second day of October. And then BAM, Mother Nature served up a week of sunshine and summer temps. Which, when you live in Canada especially, is something you don’t take for granted or ignore or treat with anything except the utmost respect and gratitude. So I stashed away the Dutch oven, moved aside the slow cooker for the week, and threw some burgers on the barbeque for a little summer Swan song.

And when I say I threw some burgers on the barbeque, *I* actually did do that. Well maybe not the throwing part. But the point is that it was me, myself and I doing the barbecuing. The barbie was always Kiwi’s beast, but this year I did a big female-empowerment kinda thing by teaching myself how to use it. This means that not only do we now have dinner before 9 p.m., BUT we have also done away (at least on weekdays) with the whole husband-taking-credit-for-a-dinner-he-did-not-cook thing. You know what I mean, right? When the ladies/moms spend all week planning the meal and all day in the kitchen chopping, saucing and prepping, and then the men/dads flip a steak and are all “Isn’t this amazing?” “This is soooo tender!” “Cooked to perfection! Huzzah!” “What a great meal I made!”. Ugh. Just, ugh.

This recipe is for a pretty classic burger, but jazzed up with the most synergistically awesome flavour-enhancers of all time: mushrooms, caramelized onions and old cheddar. The caramelized onion part means that the patties are a tad bit more time-consuming than my usual fare. But the time is well, well worth it for the extra flavour punch. Just trust me on this one. If you have the luxury of planning this meal in advance (like, ahem, as part of a meal plan or something crazy like that), then you can make the caramelized onions and sauteed mushrooms a day or two ahead of time, which is what I usually do and highly recommend. Caramelizing onions is a relatively hands-off job, so you can let it happen on the back of the stove while you are cooking dinner, making lunches or watching old episodes of MasterChef on your iPad.

Mushroom, Cheddar & Caramelized Onion Burger | (Cooking for) Kiwi & Bean

Be sure to get GOOD meat for these burgers. I am a little wary of the standard-issue grocery store ground beef, myself, so I either ask my local butcher to grind up a big hunk of chuck. Or I buy the hunk and grind it myself using an attachment for my KitchenAid stand mixer. Either way, be sure not to use that extra-lean ground stuff, and go for something with a decent amount of fat.

This recipe makes a good-sized batch, and I either freeze the remaining burgers for another night (put a piece of parchment between them so they don’t stick together), or turn half the meat mixture into mini burgers, and then bake (at 400 for about 20 minutes), cool, freeze, and serve them up to my kiddos for a quick lunch or dinner.

We ate our burgers on lettuce leaves, because the kids were in bed and, you know, skinny jeans and all that jazz. But buns work too, obviously. Topped off with some quick-pickled red onions, tomato and avocado, and aside some butternut squash “fries”, these burgers are the perfect summer-in-fall dinner.

Mushroom, Caramelized Onion & Cheddar Burgers

Prep Time: 45 minutes

Cook Time: 10 minutes

Total Time: 55 minutes

Yield: 8 burgers


  • 2 pounds good quality ground beef
  • 2 onions, sliced in thin half moons
  • 1/2 pound mushrooms, thinly sliced
  • 2 tablespoons extra virgin olive oil
  • 1 tablespoon balsamic vinegar
  • 1 cup grated extra old cheddar cheese
  • Few sprigs fresh thyme
  • Salt and pepper


  1. Heat the olive oil in a large skillet set over medium heat. Add the onions, and let them cook, stirring every few minutes, until they are very soft and very brown. If they start to look dry, drizzle in the balsamic vinegar.
  2. When the onions are cooked, remove them to a bowl and add the sliced mushrooms to the pan. Do NOT flip them over or even touch them until they turn brown, then flip them and let the other side brown. When they are nice and brown, take them off the heat and dump them into the onion bowl.
  3. Let the onion-mushroom mixture cool, and then chop it up very finely. Combine the chopped onion-mushroom mixture with the ground beef, thyme and cheddar. Gently mix it all together with your hands, and then form into 8 burger patties.
  4. Season the patties with salt and pepper just before putting them on the grill. Grill them to desired doneness, and serve on buns or lettuce leaves.


9 Responses to Mushroom, Caramelized Onion & Cheddar Burgers

  1. Peter32 May 27, 2018 at 6:13 am #

    I very like to read such posts, they are really interesting.

  2. Jennifer Andrews October 3, 2014 at 7:20 pm #

    “Summer in fall” sums it up perfectly! Great recipe, the caramelized onions sound absolutely delicious for this burger. I also love the fact that you used lettuce cups instead if buns…I do this often and find that if anything it lets you taste more burger!

    • Sarah October 6, 2014 at 2:25 pm #

      Yes, i totally agree you can really taste the burger so much better than when it’s hidden in a bunch of bun!

  3. Deidre Tansey October 3, 2014 at 3:02 pm #

    You had me at caramelized onions! I have been renewing my love of all things onion lately…thanks for sharing this delicious recipe and I LOVE your photographs. Gorgeous 🙂

    • Sarah October 6, 2014 at 2:25 pm #

      Thanks, Deidre 🙂

  4. Laureen Fox October 3, 2014 at 2:16 pm #

    Looks like the perfect meal to me! I didn’t start eating bunless burgers until after I went gluten free and now that’s the only way I like them.

    • Sarah October 6, 2014 at 2:26 pm #

      Yup, perfect meal :-). Thanks for stopping in Laureen!

  5. Sach October 2, 2014 at 12:38 pm #

    OMG these look delicious, and easy to follow prep too. Gonna try them this weekend 🙂

    • Sarah October 2, 2014 at 2:58 pm #

      Doooo it! And let me know how you like them!

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