Jalapeño-Onion Smash Burgers

These Jalapeño-Onion Smash Burgers deliver juicy beef with crispy bits, savory caramelized onions, and jalapeños that bring both heat and zing. The classic smash burger gets a spicy update here, making this a favorite for my family on burger night or anytime we want something with a little kick.

When I first made these, everyone in my house kept coming into the kitchen just to grab a taste of the onions and jalapeños off the skillet. These burgers disappear even faster than classics because the spicy twist really stands out.

Ingredients

• Mayonnaise: Essential for creamy burger sauce and helps meld all the flavors
• Ketchup: Adds tang and slight sweetness for balance
• Worcestershire sauce: Brings umami and depth to the sauce so do not skip or swap
• Black pepper: Freshly ground gives brighter flavor than pre-ground
• Garlic powder: Subtle savory note to deepen the sauce
• Kosher salt: Controls the overall taste and helps draw sweetness from the onions
• Ground beef: Look for 80 percent lean for a juicier burger and ask your butcher to grind it fresh if possible
• Canola oil: Neutral oil that can take high heat so the burgers sear perfectly
• Yellow onion: For rich caramelization which adds natural sweetness that balances the heat
• Jalapeño chile: Choose ones that feel firm and glossy for kick and crunch
• American cheese: Classic for perfect melt and creaminess
• Hamburger buns: Go for bakery buns if you can and always toast them for best texture

Step-by-Step Instructions

Prepare the Burger Sauce:

Mix mayonnaise ketchup Worcestershire sauce black pepper garlic powder and kosher salt together in a small bowl until fully combined

Cover and place in the fridge to chill while you prepare the rest

Cook the Onions and Jalapeños:

Warm your cast-iron skillet over medium heat then add canola oil making sure the surface is coated

Add sliced onions and jalapeños then season them with a bit of salt and pepper

Stir regularly letting the mixture cook for about ten to fifteen minutes until onions are golden and jalapeños look soft

Transfer them to a bowl and set aside for topping

Form the Burger Patties:

Gently divide ground beef into eight portions each about three ounces

Roll each into a loose ball taking care not to pack tightly so the patties remain juicy

Chill the beef balls on a baking sheet in the fridge until you are ready to cook

Smash and Cook the Burgers:

Wipe your skillet clean and heat it on high until you see the first wisp of smoke

Add a few beef balls at a time making sure there is plenty of space between them

Use a sturdy spatula or burger press to smash each ball flat as thin as possible

Immediately season each patty with a pinch of the remaining salt and pepper

Sear for two to three minutes without moving allowing a crisp crust to form

Flip each patty and set a slice of cheese on top letting it melt as the second side finishes cooking

Assemble and Serve:

Generously spread burger sauce on both the top and bottom buns

Set a cheesy patty on the bottom bun

Spoon over a nice portion of caramelized onions and jalapeños

Add any extras you love then finish with the top bun

Eat right away while everything is hot and melty

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My favorite part is piling on the onion and jalapeño mixture. Every time I make this I am reminded of backyard cookouts with my cousins where the peppers always stole the show.

Storage Tips

Leftover cooked burger patties and toppings can be kept in the fridge for up to two days. Store patties and buns separately to keep buns from getting soggy. Reheat patties in a hot skillet for best texture.

Ingredient Substitutions

You can swap American cheese for cheddar or pepper jack if you want a different melt or more spice. Red onions can be used instead of yellow for a sharper taste. For milder heat remove the seeds from the jalapeños.

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Serving Suggestions

I love serving these smash burgers with crispy French fries or a cool side salad. Pickled jalapeños or coleslaw also work well for a tangy crunch.

Recipe FAQs

→ How do you achieve crispy burger edges?

Using a hot cast-iron skillet and firmly pressing each beef ball with a sturdy spatula creates crispy, caramelized edges.

→ Can the level of spiciness be adjusted?

Absolutely. For less heat, remove the seeds and membranes from the jalapeños before slicing and cooking.

→ What type of cheese works best?

American cheese melts smoothly and complements the flavors, but cheddar or pepper jack are also excellent choices.

→ How can I keep the patties tender?

Handle the ground beef gently and avoid overworking it when forming balls, which preserves juiciness and texture.

→ What are great sides to serve with these burgers?

Classic sides like fries, sweet potato fries, or a crisp green salad pair perfectly with the burgers.