How To Make In-N-Out Grilled Onions

How To Make In-N-Out Grilled Onions: Expert Guide

Last Updated on July 17, 2024 by Shari Mason

Perfecting how to grill onions is a crucial step in replicating the ultimate In-N-Out burger experience.

As a seasoned chef with firsthand experience, I’ve unlocked the secrets to achieving those irresistible, caramelized onions that take your homemade burgers to the next level. 

I’ll answer five burning questions to help you perfect the art on how to make In-N-Out grilled onions. Get ready to impress your taste buds.

Ultimate Recipe For In-N-Out Grilled Onions

Close Up Image of Grilled Onion


  • 2 large yellow onions
  • 2 tablespoons vegetable oil or melted butter
  • Salt, to taste
  • Freshly ground black pepper, to taste


  1. Start by peeling the onions [1] and cutting them into thin slices. Separate the onion layers gently to allow for more surface area during grilling.
  2. Preheat your grill or stovetop griddle to medium-high heat. If using a grill, ensure the grates are clean and lightly oiled.
  3. Drizzle the vegetable oil or melted butter evenly over the cooking surface of the grill or griddle.
  4. Spread out the onion slices in a single layer on the hot surface. Let them cook undisturbed for about 5 minutes or until they develop a golden-brown color.
  5. Flip the onions over using tongs and cook for an additional 5 minutes or until they are caramelized to perfection. Adjust the cooking time as needed to achieve your desired level of caramelization.
  6. Sprinkle the grilled onions with salt and freshly ground black pepper to taste. Toss them gently to distribute the seasoning evenly.
  7. Remove the grilled onions from the heat and transfer them to a serving dish. They are now ready to be used in your In-N-Out-style burgers.
  8. Assemble your burger by layering the grilled onions on top of the beef patty, allowing their sweet and savory flavors to meld with the other components. Add your preferred condiments, cheese, lettuce, and tomato, and place the assembled burger between a soft, toasted bun.
  9. Serve your homemade In-N-Out-style burger with grilled onions immediately, and enjoy the deliciousness!

“ It doesn’t matter how precisely the onion is cut as long as the person chewing it is happy.”

– Padma Lakshmi, Indian-American Writer

What’s The Best Way To Achieve That Signature Caramelized Goodness?

Grilling Onions
  1. Choose the correct pan: Opt for a heavy-bottomed pan like stainless steel or cast iron skillet. These pans distribute heat evenly and help in achieving consistent caramelization.
  2. Use low to medium heat: Caramelization is slow, so starting with low to medium heat is essential. This allows the sugars to gradually break down and develop rich flavors without burning.
  3. Add sugar: Sprinkle a thin, even layer of granulated sugar over the pan’s surface. As the sugar heats up, it will melt and caramelize. You can also use other types of sugar, like brown sugar or palm sugar, for a deeper flavor.
  4. Patience is vital: Avoid the temptation to stir the sugar too frequently. Let it sit undisturbed as it melts and begins to caramelize. You can gently swirl the pan occasionally to ensure even browning.
  5. Add butter: Once the sugar has melted and turned golden brown, add a small amount to enhance the flavor and richness. Stir it into the caramelized sugar until it’s fully incorporated.
  6. Control the heat: If you notice the caramelizing process is happening too quickly or the sugar is in danger of burning, reduce the heat slightly or move the pan off the heat for a moment. Adjust the heat as needed to maintain a steady caramelization.
  7. Consider flavor variations: For additional depth of flavor, you can incorporate other ingredients like vanilla extract, sea salt [2], or a splash of liqueur. These additions can elevate the taste of your caramelized creation.

“Like whispered secrets on a summer breeze, the art of crafting In-N-Out’s grilled onions dances upon the grill, transforming humble bulbs into caramelized symphonies.” 

– Eat Pallet Restaurant & Food Advice

How Can I Add Extra Flavor To The Grilled Onions?

  1. Brush them with a marinade or glaze before grilling.
  2. Create a mixture using ingredients like olive oil, balsamic vinegar, honey, soy sauce, minced garlic, and herbs or spices.
  3. Let the onions sit in the marinade for at least 30 minutes to allow the flavors to penetrate.
  4. While grilling, baste the onions with the marinade to keep them moist and infuse them with additional taste.
  5. You can also sprinkle them with a pinch of sea salt, black pepper, or smoked paprika for added depth.
  6. Top the grilled onions with a squeeze of fresh lemon or lime juice and a handful of chopped fresh herbs such as parsley or cilantro. 


u003cstrongu003eCan I grill the onions ahead of time and reheat them later?u003c/strongu003e

Yes, you can grill the onions ahead of time and reheat them later. After grilling, allow the onions to cool, then store them in an airtight container in the refrigerator. u003cbru003eu003cbru003eWhen you’re ready to serve, reheat the grilled onions on a grill, stovetop, or oven until heated. u003cbru003eu003cbru003eReheating methods may vary depending on your preference and the equipment available.

u003cstrongu003eCan I achieve the same results with a stovetop pan instead of a grill?u003c/strongu003e

Yes. You can definitely achieve the same results with a stovetop pan instead of a grill.

Key Takeaways

In-N-Out grilled onions can be delicious by following a few key steps. Start by thinly slicing onions and cooking them in a hot pan with a small amount of oil or butter. 

Allow the onions to caramelize slowly over medium heat, stirring occasionally to ensure even browning. 

Season the onions with a sprinkle of salt and continue cooking until they reach a golden-brown color with a sweet and savory flavor. 

The caramelized grilled onions can be used to top burgers, hot dogs, sandwiches, or even as a side dish. 

With patience and attention to detail, you can recreate the mouthwatering In-N-Out grilled onions at home to enhance your favorite dishes.


Shari Mason

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