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5 from 1 vote

Mushroom burgers with caramelized onions.

If you are looking for the best burger, this is your recipe. The combination of the beef, mushrooms, and caramelized onions is the best!!
Prep Time40 mins
Total Time40 mins
Course: Main Course
Cuisine: American
Keyword: beef, mushrooms, onions
Servings: 4
Author: Amy- A Red Spatula


Caramelized Onions

  • 3 cups onions, sliced
  • 2 teaspoons olive oil
  • ¼ teaspoon salt

Rosemary and Pepper Aioli

  • cup mayo
  • 1 teaspoon rosemary
  • ½ teaspoon ground black pepper
  • 1 teaspoon lemon juice
  • salt to taste

Sauteed Mushrooms

  • 5 cups sliced mushrooms
  • 1 tablespoon olive oil
  • ½ teaspoon salt


  • 1- ½ pounds ground beef
  • 2 tablespoons salt
  • 1 teaspoon ground black pepper
  • ½ teaspoon paprika
  • ½ teaspoon cayenne
  • 1 teaspoon garlic powder
  • 4 hamburger buns
  • 4 slices swiss cheese


Caramelized onions

  • There are a few things that will need to happen at the same time, but in this recipe, let me tell you how I do it. Start with the onions, as they will take the longest.
  • Heat a nonstick skillet over medium heat. Add olive oil and heat. Add in onions and turn heat to medium-low. Add salt. Saute, stirring occasionally until the onions have turned a deeper caramel color. This will take a while, so be patient. It will probably take at least 20-25 minutes. You can use them right away or even store them in an airtight container in the fridge for up to 4 days.


  • Mix all ingredients for the aioli while the mushrooms and cooking. Taste and check for salt. Add it as needed.

Burgers and Shrooms

  • While the onions are cooking, prep the mushrooms and the burgers.
  • Mix the seasoning for the burgers. Form 4 patties and season them with the seasoning,
  • Heat nonstick or cast-iron skillet over medium heat. Add olive oil and heat. Next add in mushrooms, salt, and garlic. Cook, stirring occasionally until the mushrooms are tender and have shrunk. Mine took about 5 minutes.I prefer to use my mushrooms right away. They can be stored in an airtight container for up to 2 days if you need to.
  • Now, heat your grill or cast-iron skillet as I did. You will want it pretty hot before you add the burgers.
  • Once it is heated, add the burgers. Cook for about 3-6 minutes per side, depending on how you take your burger.
  • Next, assemble the burgers. Add the burger to your bun, then the mushrooms, onions, and swiss cheese.
  • Last, slather with the aioli!
  • You are done. Sit back and enjoy. You deserve it!