Portobello Blue Cheese Burgers
A discovery of 2021 that I had questioned for far too long is the substitution of portobello mushrooms for the bun of a burger. The concept always interested me, but I'd never tried it until a few months ago. Wow, did it change my perspective on low-carb swaps (for the better).
First off, I’m a BIG mushroom gal. Karen & Collier (hi mom and dad!) will be the first to tell you that my go-to Outback meal as a child was the penne pasta Mac-n-cheese (an elite menu item, might I add) with a side of sautéed mushrooms. Don’t ask why this combination of food was my meal; the point is, I’ve always loved mushrooms and that love has not dissipated from my Outback days. So this concept was subjectively off to a favorable start.
I get it, most people aren’t mushroom fans. It’s one of those foods that you either love or hate in my mind and the texture can be quite wonky. But if you love em, I can assure you this burger will rock your world. A portobello is such a sturdy, thick mushroom that I can promise you won’t even miss the bread for a bun.
Here’s the thing. I’ve listed below what I think would be a perfect bite of a burger—beef, blue cheese, onions, all the dirty works! But if you hate blue cheese, just use something different. I’m not the burger police, people—do what serves you. For example, a white cheddar or Muenster cheese would be a power move in replacement of blue cheese. The avocado mayo and caramelized onions are what really set this burger off, though, so I recommend staying the course with those ingredients. Just have some fun with it! Don't allow this burger to stress you out.
Disclaimer: Do not eat these on a first date or far from napkins. Things are going to get juicy and messy, very fast. Buckle up, caramelize some onions low & slow, use blue cheese (or don’t!), and report back just how satisfying this burger is. Mushroom gang stand up because this is about to blow your mind.
As always, may the inspiration found here find light in your kitchen.
1 lb ground beef*
8 portobello mushroom caps
1 avocado, mashed
1/4 c Duke's mayo
1 onion, sliced & caramelized
Balsamic glaze, to taste
*makes 4 quarter-pound burgers
How to make it happen
Cut ground beef into 4 equal parts, shape into patties, and season with a grill rub [of your choice] and add Worcestershire sauce. Let sit at room temperature for about 20 mins.
Heat a grill or grill pan to medium/high heat. Brush with olive oil.
Clean out stems from portobello mushroom caps and sear on grill about 2-3 mins each side, or until grill marks appear on each side. Remove from grill and set aside.
Cut one onion into long, thin strips and put into a low/medium heat pan with a teaspoon of butter. Sprinkle with salt and cook for about 20 mins, stirring frequently to caramelize the onions. Set aside once golden brown on edges.
On the same grill you used for the mushrooms, cook beef patties to temperature of your liking, about 4 mins each side for a medium-rare finish. Add blue cheese on top of burger when you flip.
While burgers cook, mash an avocado and mayo together until smooth. Lay each of your portobello mushrooms facing up (aka the underside, or better known as the black gills side). Add dollops of avocado mayo to all portobello mushroom caps.
Place a burger from the grill on top of 4 mushrooms, top with onions and balsamic glaze, and close the burger with remaining 4 mushrooms.
Grab some napkins and enjoy!