French Onion Beef Sliders Recipe

French Onion Beef Sliders Recipe | Savory & Juicy Mini Burgers

I just made these French Onion Beef Sliders recipe and I have to tell you — they disappeared faster than I expected. Picture sweet, slow-cooked onions mingling with seasoned ground beef, all tucked into soft slider buns and smothered in melty cheese. I felt like I was serving a party favorite, but honestly, I just made them for myself and little did I know I’d be dreaming about leftovers.

These sliders are absolutely crowd-pleasing, and I can’t wait to walk you through how you can make them too. You might also enjoy similar flavors in the Creamy French Onion and Mushroom Soup Recipe, which has a rich, savory base perfect for comfort meals.

Ingredients

Here’s what you’ll need to make about 24 sliders, based on the original recipe.8 tablespoons (1 stick) butter, divided — the butter adds richness for both the onions and the topping glaze.

• 2 large sweet onions, thinly sliced — using sweet onions helps caramelize nicely without becoming too bitter.
• 2 pounds ground beef — the base protein; leaner or fattier works, but moderate fat gives better flavor.
• 2 tablespoons beef base (such as Better Than Bouillon), divided — this concentrated flavor brings savory depth without using too much liquid.
• 1 tablespoon Worcestershire sauce, divided — helps boost the umami taste and ties together the beef and onion flavor. 
• Kosher salt and freshly ground black pepper, to taste — simple seasoning to enhance all the other flavors. 
• 24 slider buns — soft, small buns are ideal to make these true “sliders.” )
• 12–16 ounces Gruyère or Swiss cheese, shredded — this cheese melts beautifully and pairs excellently with the savory beef and onions. 
• 2 tablespoons sesame seeds — sprinkled on top for a little crunch and visual appeal. 
• 1 tablespoon fresh thyme — adds a slight herbaceous note that complements the beef. 
• 1 teaspoon onion powder — intensifies that onion-flavor throughout. 
• 1 teaspoon garlic powder — for a subtle garlicky background taste. 

Note: This recipe makes approximately 24 sliders, depending on how generously you fill the buns.

Variations

If you want to tweak this recipe to suit different tastes or dietary needs, here are some variations you can try:

• Dairy-free: Swap regular butter for a plant-based margarine, and use a non-dairy cheese alternative (e.g., vegan “Swiss” shreds) instead of Gruyère or Swiss cheese.
• Lower sodium / reduced bouillon: Use less beef base or opt for a reduced-sodium option; replace part of the flavor with a splash of low-sodium beef broth.
• Healthier meat: Instead of 2 lb of ground beef, you could use ground turkey or a lean beef mix to cut fat.
• Extra flavor kick: Stir in sautéed mushrooms with the onions, or add a pinch of red pepper flakes to the glaze for a mild heat.
• Herb variation: Replace fresh thyme with rosemary or chopped basil to give a different aromatic twist.

You can also enjoy these sliders alongside a creamy, cheesy option like the Best Boursin Chicken Recipe for a full comfort-food spread.

Cooking Time

Here’s a breakdown of how long each step takes:

• Prep Time: ~20 minutes 
• Cooking Time: ~1 hour (this includes caramelizing onions + baking sliders) 
• Total Time: ~1 hour 20 minutes 

Equipment You Need

To make these sliders easily, you’ll want:

• A large skillet – for caramelizing the onions and browning the beef.
• A large mixing bowl – to combine the ground beef with seasonings before cooking.
• A baking sheet – to assemble and bake the sliders in the oven.
• A pastry brush – for brushing the butter-beef glaze over the top buns.
• A knife – to slice your onions and separate burger rolls.

How to Make French Onion Beef Sliders

Caramelize the Onions

First, melt 2 tablespoons of butter in your skillet over medium heat, then add the sliced sweet onions. Reduce the heat to medium-low and cook the onions slowly, stirring occasionally, for about 25–30 minutes until they turn golden and slightly sweet. This low-and-slow approach is key for deep, rich caramelization. 

Mix and Brown the Beef

While the onions are cooking, combine the ground beef in a bowl with half of the beef base and half of the Worcestershire sauce. Season with kosher salt and black pepper.

Then add this meat mixture to the skillet with the onions, turn the heat up to medium-high, and break the beef up as you brown it, making sure it mixes well with the onions. When fully cooked, drain off any excess grease. 

Assemble the Sliders

Preheat your oven to 350°F (175°C). Lightly grease your baking sheet. Separate the tops and bottoms of the buns, and pack the bottom halves snugly on your sheet. Spread the beef-and-onion mixture evenly over the bottoms, then sprinkle the shredded Gruyère (or Swiss) cheese on top. Close each slider by placing the bun tops back on. 

Make the Glaze & Bake

In a microwave-safe bowl (or over low heat), melt the remaining 6 tablespoons of butter with the rest of the beef base and the remaining 1/2 tablespoon of Worcestershire sauce.

Use your pastry brush to paint this flavorful glaze over the top buns. Then sprinkle sesame seeds, fresh thyme, onion powder, and garlic powder evenly over the glazed tops. Bake for about 20 minutes, until the cheese has melted and the tops are lightly browned. 

Additional Tips for Making This Recipe Better

Here’s what I learned when I made these sliders — little tweaks that made a big difference:

• I found that stirring the onions gently and patiently while they cook makes all the difference: don’t rush them, or they’ll burn.
• I like to refresh the pan with a splash of water if the onions are drying out; it helps lift the caramelized bits.
• I used freshly shredded cheese instead of pre-shredded — it melts more smoothly and tastes better.
• While brushing on the butter-bouillon glaze, I made sure to brush over every nook of the top buns, so each slider has that savory, buttery crust.
• I let the baked sliders rest for a minute after coming out of the oven, just so the cheese sets a little (makes them easier to pick up).

How to Serve French Onion Beef Sliders

These sliders are super versatile when it comes to serving:

• Party platter: Arrange them on a wooden board, sprinkle a few extra thyme leaves on top, and stick toothpicks into them so guests can grab easily.
• Meal accompaniment: Pair them with crunchy potato chips, a crisp green salad, or even fries for a comfort-food-style dinner.
• Garnish ideas: A dash of extra fresh thyme, a drizzle of au jus (if you have some), or a side of caramelized onion dip makes them look elegant.
• Warm presentation: Serve them right out of the oven while the cheese is gooey — trust me, that’s when they shine.

Nutritional Information

Here’s a rough estimate of the nutrition per one slider (out of 24), based on the source recipe:

• Calories: ~290 kcal 
• Protein: ~14 g 
• Carbohydrates: ~18.6 g 
• Fat: ~17.4 g 

Make Ahead and Storage

Storing

Once the sliders have cooled to room temperature, I store them in an airtight container in the fridge. They stay good for up to 5 days, per my experience, and the flavors actually deepen overnight.

Freezing

If I want to save them longer, I tightly wrap the whole tray (or individual sliders) in plastic wrap and then aluminium foil, and freeze them for up to 2–3 months. When ready, I thaw them in the fridge first.

Reheating

To reheat, I like to cover them with foil and warm in the oven at about 350°F for 10–15 minutes (or until the cheese is bubbly again). If I’m in a rush, I reheat individual sliders in the microwave for 20-30 seconds, though oven is my favorite.

Why You’ll Love This Recipe

Here are a few reasons these sliders are a winner (from my kitchen to yours):

• Perfect for entertaining: They make about 24 sliders, so they’re ideal for parties or large gatherings.
• Rich, savory flavor: The mix of caramelized onions, beef base, and melted cheese delivers deep, delicious umami.
• Make-ahead friendly: You can prep in advance, refrigerate or freeze, and bake when you’re ready.
• Customizable: You can switch up the cheese, use different buns, or even go dairy-free — the base recipe is very flexible.
• Comfort food with finesse: These sliders feel indulgent but aren’t complicated — kind of like gourmet meets appetizer.

Ben Carraoli

French Onion Beef Sliders Recipe

I just made these French Onion Beef Sliders and I have to tell you — they disappeared faster than I expected. Picture sweet, slow-cooked onions mingling with seasoned ground beef, all tucked into soft slider buns and smothered in melty cheese.

Print Recipe Pin Recipe

Prep Time 20 minutes mins

Cook Time 1 hour hr

Ingredients Method Notes

Ingredients

  

• 2 large sweet onions thinly sliced — using sweet onions helps caramelize nicely without becoming too bitter.
• 2 pounds ground beef — the base protein; leaner or fattier works but moderate fat gives better flavor.
• 2 tablespoons beef base such as Better Than Bouillon, divided — this concentrated flavor brings savory depth without using too much liquid.
• 1 tablespoon Worcestershire sauce divided — helps boost the umami taste and ties together the beef and onion flavor.
• Kosher salt and freshly ground black pepper to taste — simple seasoning to enhance all the other flavors.
• 24 slider buns — soft small buns are ideal to make these true “sliders.” )
• 12 –16 ounces Gruyère or Swiss cheese shredded — this cheese melts beautifully and pairs excellently with the savory beef and onions.
• 2 tablespoons sesame seeds — sprinkled on top for a little crunch and visual appeal.
• 1 tablespoon fresh thyme — adds a slight herbaceous note that complements the beef.
• 1 teaspoon onion powder — intensifies that onion-flavor throughout.
• 1 teaspoon garlic powder — for a subtle garlicky background taste.

Method

 

1. First, melt 2 tablespoons of butter in your skillet over medium heat, then add the sliced sweet onions. Reduce the heat to medium-low and cook the onions slowly, stirring occasionally, for about 25–30 minutes until they turn golden and slightly sweet. This low-and-slow approach is key for deep, rich caramelization.
2. While the onions are cooking, combine the ground beef in a bowl with half of the beef base and half of the Worcestershire sauce. Season with kosher salt and black pepper. Then add this meat mixture to the skillet with the onions, turn the heat up to medium-high, and break the beef up as you brown it, making sure it mixes well with the onions. When fully cooked, drain off any excess grease.
3. Preheat your oven to 350°F (175°C). Lightly grease your baking sheet. Separate the tops and bottoms of the buns, and pack the bottom halves snugly on your sheet. Spread the beef-and-onion mixture evenly over the bottoms, then sprinkle the shredded Gruyère (or Swiss) cheese on top. Close each slider by placing the bun tops back on.
4. In a microwave-safe bowl (or over low heat), melt the remaining 6 tablespoons of butter with the rest of the beef base and the remaining 1/2 tablespoon of Worcestershire sauce. Use your pastry brush to paint this flavorful glaze over the top buns. Then sprinkle sesame seeds, fresh thyme, onion powder, and garlic powder evenly over the glazed tops. Bake for about 20 minutes, until the cheese has melted and the tops are lightly browned.

Notes

• I found that stirring the onions gently and patiently while they cook makes all the difference: don’t rush them, or they’ll burn.
• I like to refresh the pan with a splash of water if the onions are drying out; it helps lift the caramelized bits.
• I used freshly shredded cheese instead of pre-shredded — it melts more smoothly and tastes better.
• While brushing on the butter-bouillon glaze, I made sure to brush over every nook of the top buns, so each slider has that savory, buttery crust.
• I let the baked sliders rest for a minute after coming out of the oven, just so the cheese sets a little (makes them easier to pick up).