Mushroom Beef Burgers with Grilled Onions

This post may contain affiliate links which won’t change your price but will share a commission.

Mushroom Beef Burgers blend seasoned ground beef with finely chopped mushrooms for a juicy, umami-rich patty that’s both hearty and flavorful. Top these burgers with cheese, grilled red onions, and smashed avocado – and then enjoy every single bite!

Two hands holding a mushroom beef burger with avocado.

Mushroom Burgers

Adding mushrooms to recipes is a bit of an obsession of mine, so it just makes sense to create a mushroom burger. But let’s be clear. This is not a meat-free recipe, but instead it’s a beef and mushroom combo. You get the best of both worlds – meat plus our favorite veggie – mushrooms!

So as you know, mushrooms produce a lot of liquid when you cook them. You’ll need to handle the burgers with care while grilling because they are prone to falling apart. But you won’t be mad about how they literally melt in your mouth while eating them – I promise! They’re so delicious, especially with seasoning (yes, taco seasoning or anything you like), melty cheese, smashed avocado, and some grilled red onion.

Why This Recipe Works:

UNAMI FLAVOR – Umami is that rich, savory flavor that makes things taste extra satisfying—kind of like the deep, meaty taste you get from mushrooms, soy sauce, or cheese.
TENDER TEXTURE – As the burgers cook, the mushrooms release liquid making the burgers extra tender. Like melt-in-your-mouth tender!
EXTRA NUTRIENTS – Mushrooms are super healthy – they’re low in calories but packed with nutrients, antioxidants, and compounds that help your immune system, brain, and gut.
DELICIOUS SPIN ON BURGERS – While we love a cheese-stuffed juicy Lucy, we also love to pile on the veggies with this beef mushroom burger. Btw, the jalapeño is optional of course, but you know how I love a little heat!

Side view of the grilled mushroom beef burger on the bottom half of bun with grilled onions and mashed avocado on the other half.

What You’ll Need:

ground chuck or beef
cremini mushrooms
jalapeno
taco seasoning
red onion
cheese
avocado
brioche buns

Labeled ingredients for the mushroom beef burgers.

How to make Mushroom Beef Burgers:

Step 1
Clean mushrooms. To clean mushrooms, gently wipe them with a damp paper towel or give them a quick rinse and pat dry – just don’t soak them, or they’ll get soggy.

Step 2
Process mushrooms. Add cleaned mushrooms to a large food processor. Pulse until the mushrooms become tiny bits. You’ll need to scrape down the sides several times.

A food processor of the whole mushrooms.

A food processor of the small mushroom pieces.

Step 3
Combine ingredients. In a mixing bowl, combine ingredients – ground chuck, processed mushrooms, diced jalapeño, and taco seasoning. Use your hands to gently combine so that the ingredients are evenly dispersed.

Step 4
Form burger patties. Divide the burger ingredients into four even sections and use your hands to form patties. Place formed patties on a pan and cover tightly until ready to cook.

Step 5
Prepare grill. Light an outdoor grill (or cook on your stovetop on a grill pan) to medium-high heat. Let it get nice and hot while relaxing with a Cherry Margarita or your choice of drink!

Step 6
Grill burgers and onions. Gently set the prepared mushroom beef burgers on the hot grill grates and season with your choice of seasoning. Add the onions too.

Grill burgers until they reach your desired temperature, flipping burgers about halfway through. Add cheese at the very end and let melt. Turn onions to get them browned.

We use a digital thermometer and prefer medium-rare. These burgers cook extremely fast so watch closely. See temperature chart below for more details.

Burger Doneness Temps:

Rare: 120 – 125 F
Medium Rare: 130 – 135 F
Medium: 140-145 F
Medium Well: 150 – 155 F
Well Done: 160 – 165 F

View of our Big Green Egg heated up and smoky.

The burgers and red onions on the grill.

Step 7
Toast buns. After you remove the mushroom burgers and grilled onions, turn heat down and place buns on the grill, cut side down. Grill until toasty.

Step 8
Prep avocado. Smash avocado with a fork. Season with salt and pepper.

Step 9
Assemble sandwiches. Place the grilled burgers on toasted buns. Top with smashed avocado and grilled onions. Enjoy!

Four beef mushroom burgers with cheese on a plate.

Overhead view of a plate of the burger before adding avocado and the top half of bun.

What to serve with mushroom beef burgers:

Potatoes or fries – Try our Small Potatoes on the Grill, Baked Garlic Home Fries, or Spicy Baked Sweet Potato Fries!
Pasta salad – How about our go-to Lemon Orzo Pasta Salad, Greek Tortellini Pasta Salad, or Creamy Pesto Pasta Salad?
Dessert please – Let’s finish this meal with some S’mores Cookie Bars, Triple Chocolate Brownies, or Butterscotch Ice Cream!

Recipe FAQs:

How do I prepare the mushrooms for the burgers?

To prepare the mushrooms, simply place them in a food processor and pulse until fine.

How should I cook the mushroom beef patties?

Cook them on an outdoor grill (or use a cast iron skillet indoors) for 4-5 minutes per side. Cook them according to your desired doneness.

What toppings work well with mushroom beef burgers?

In addition or instead of the toppings listed (cheese, avocado, and grilled onions), you could add lettuce, tomato, pickles, other types of cheese (Swiss, cheddar jack, provolone), ketchup, mustard, or a sauce (Pesto Mayo or Chipotle Ranch Dressing).

Other Delicious Burgers:

There is nothing better than a grilled juicy burger!

Side view of a mushroom burger with cheese.

Kitchen Tools Used: (affiliate links)

xoxo ~Sue