I’d say that sauteed mushrooms and onions are one of the best toppings for a burger in the world. And, the “old-standbys” become that way for good reason – because they’re awesome. The preparation of the mushroom and onions takes but a few minutes, but lifts your burger into a different stratosphere than a plain ol’ cheeseburger.
I was actually planning on making these In-n-Out copycats, when I realized I was out of pickles (the horror!) so had to change my tactics. I had a half of a package of mushrooms in the fridge, so I thought this would be the perfect opportunity to use them! Sauteed them with onion until golden, grilled the burgers, let the gooey Swiss melt – dinner was served, and it was a damn fine burger!
This really just made me hungrier for backyard BBQ’s with friends in the months ahead. Also, the beach! My mom & dad got us a portable Weber propane grill this year for Christmas. So, we’re looking forward to grilling burgers both bayside and oceanside this year! It’s also great to take to the park and grill some hot dogs for lunch while the boys play. And, I love that I can do it by myself – without Jon’s help. I see us getting quite a bit of use out of it in the coming months. Come on, summertime!
Mushroom, Onion & Swiss Burger
2 Tbsp butter
4 oz white mushrooms, sliced
1/2 medium onion, sliced thin
2 garlic cloves, minced
1 lb lean ground beef (85/15 or 90/10)
2 tsp Worcestershire sauce
2 tsp kosher salt
1 tsp ground black pepper
4 slices Swiss cheese
4 hamburger buns
Prepare your grill. Make sure it’s clean, and heat to medium-high (about 400 degrees).
In a large non-stick skillet (I like my cast iron), melt butter over medium-high heat. Add mushrooms, onions, and 1 tsp salt. Cook, stirring occasionally, until the mushrooms are tender and starting to release their liquid – about 3 minutes. Reduce heat to low, add garlic and continue to stir occasionally until mushrooms and onions are golden brown. Place in small bowl and cover with foil. Set aside.
Combine ground beef, Worcestershire sauce, 1/2 tsp salt, and 1/2 tsp pepper in a large bowl. With clean hands, gently mix to combine. Shape beef into 4 patties (a tip: I like to use an old mayo or peanut butter lid for forming my patties – makes quick work of it!). Season the patties with remaining salt and pepper.
Grill burgers over medium-high indirect heat for about 6-8 minutes, turning once, until meat thermometer reads 140 (for medium). Place cheese on top of burgers, close lid, and cook for 1 minute longer to let the cheese melt.
Place burgers on toasted buns, and divide the mushroom-onion mixture evenly over the burgers. Top with mayonnaise, if desired.