These Gruyere Caramelized Onion Sliders bring together juicy seasoned beef, deeply caramelized onions, and melty Gruyere tucked into soft toasted slider buns. I love how comforting and rich they taste while still being simple enough for a quick dinner or a party platter.
Why You’ll Love This Recipe
I enjoy this recipe because the flavor feels gourmet without requiring complicated steps. The caramelized onions add natural sweetness, the Gruyere melts beautifully over the beef, and the sliders assemble quickly once everything is prepped. I also appreciate how easy it is to scale the recipe for gatherings or casual meals.
Ingredients
(Tip: You’ll find the full list of Ingredients and measurements in the recipe card below.)
Melt the butter in a skillet over medium heat. Add the sliced onions and thyme sprigs. Reduce the heat to medium-low and cook, stirring often, until the onions are golden, soft, and caramelized, about 30–45 minutes. Remove the thyme stems and set the onions aside.
In a small bowl, mix the mayonnaise, steak sauce, and cracked black pepper. Refrigerate until needed.
In a mixing bowl, combine the ground beef, crushed bouillon, dried onion, celery seed, dried parsley, dried thyme, and pepper. Form into 12 equal meatballs.
Heat a griddle or large skillet over medium-high heat and add the tablespoon of butter. Place the meatballs on the surface and cook for 2 minutes. Flip them and press each one down firmly to form a thin patty. Cook another 2 minutes or until browned.
Sprinkle the patties generously with shredded Gruyere and let the cheese melt as the patties finish cooking. Remove from heat once the cheese is fully melted.
To assemble, place arugula on the bottom half of each toasted slider bun. Add a cheesy patty, top with caramelized onions, spread the mayo mixture on the top bun, and close each slider.
Servings And Timing
This recipe makes about 12 sliders, serving 4–6 people depending on appetite.
Approximate timing:
Prep time: 15–20 minutes
Cooking time: 45–60 minutes
Total time: 60–80 minutes
Variations
Add mushrooms: I sometimes sauté mushrooms with the onions for a deeper, earthier flavor.
Change the cheese: Gruyere is ideal, but Swiss, provolone, or sharp white cheddar work wonderfully.
Use brioche buns: For a sweeter flavor, I swap standard buns for mini brioche rolls.
Add a spicy kick: A pinch of cayenne or hot sauce in the mayo gives the sliders extra heat.
Make them larger: Shape larger patties and use full-size burger buns if I want a regular sandwich instead of sliders.
Storage/Reheating
I store leftover patties and onions separately in airtight containers in the refrigerator for up to 3 days. Slider buns stay best at room temperature in a sealed bag.
To reheat, I warm the patties in a skillet over medium heat for 3–4 minutes until heated through. I reheat onions gently in a small pan. Once warm, I reassemble the sliders fresh so the buns don’t get soggy.
FAQs
How thin should I smash the patties?
I press them to about 1/4–1/3 inch thick so they cook quickly and develop crisp, flavorful edges.
Can I caramelize the onions ahead of time?
Yes. I often make them a day in advance and refrigerate them. They reheat perfectly in a skillet over low heat.
Can I use a different meat?
Ground turkey works, though it won’t be as juicy. If I choose turkey, I add a tablespoon of olive oil to the mix for extra moisture.
What greens work best besides arugula?
Spinach, shredded lettuce, or finely shredded cabbage all add a fresh crunch.
Can I freeze the patties?
Yes. I freeze the raw patties between parchment layers, then cook them from frozen, adding 1–2 extra minutes per side.
Conclusion
These Gruyere Caramelized Onion Sliders are one of my favorite easy yet elevated meals. The combination of caramelized onions, melted Gruyere, and seasoned beef creates layers of flavor that feel special without taking all day to prepare. Whether I’m hosting or making a relaxed dinner, these sliders always deliver—and I rarely have leftovers.
Gruyere Caramelized Onion Sliders are rich, flavorful mini burgers made with juicy seasoned beef, sweet caramelized onions, and melty Gruyere cheese on toasted buns. Perfect for parties or cozy dinners, they feel gourmet yet are easy to make.
Melt 2 tbsp butter in a skillet over medium heat. Add onions and thyme sprigs. Cook on medium-low, stirring often, until deeply caramelized (30–45 minutes). Remove thyme stems and set aside.
Mix mayo, steak sauce, and cracked pepper. Refrigerate until ready to use.
In a bowl, combine ground beef, bouillon, dried onion, celery seed, parsley, thyme, and pepper. Form into 12 meatballs.
Heat 1 tbsp butter in a skillet over medium-high heat. Add meatballs, cook 2 minutes, flip, and smash into thin patties. Cook 2 more minutes.
Top each patty with Gruyere and cook until cheese is melted. Remove from heat.
Assemble sliders: layer arugula on bottom bun, add patty, top with caramelized onions, spread mayo on top bun, and close.
Notes
Caramelized onions can be made a day ahead and reheated.
Use Swiss or cheddar if Gruyere isn’t available.
To freeze raw patties, separate with parchment and store in a sealed bag.
Reheat patties and onions separately for best texture when storing leftovers.
