Name: Vegetarian Smashed Mushroom Burger with Pickled Jalapeños Recipe
Prep time: 10 min
Cook time: 13 min
Total time: 23 min
Cuisine: American
Ingredients: 2 tbsp Dark soy sauce (reduce to 1 tbsp if preferred for less saltiness); 1/2 tsp Liquid smoke; 1/4 tsp Smoked paprika; 1/2 tsp Garlic powder; 1/2 tsp Onion powder; 1 tbsp Olive oil; 1/4 tsp Oregano; 1/4 tsp Lime juice; 1/2 tsp Maple syrup; 6 ounces Oyster mushrooms; Brioche buns; 3 American cheese slices; Lots of pickled jalapeños; Sriracha mayo for spreading

Jump to Recipe· 3.9 from 72 reviews

If you crave a burger experience that bursts with bold, smoky flavors but stays completely plant-based, you are going to adore this Vegetarian Smashed Mushroom Burger with Pickled Jalapeños Recipe. The star here is the oyster mushroom, marinated and seared to perfection until tender yet crispy on the edges, layered with melty American cheese and tangy, spicy pickled jalapeños, all hugged by a soft, buttery brioche bun. Every bite offers a mouthwatering blend of smoky, sweet, and spicy notes that will satisfy burger lovers and vegetarians alike. This recipe is a true game-changer for anyone looking to elevate their meatless meals without any compromise on flavor or texture.

Ingredients You’ll Need

The image shows a close-up of two dark brown, almost blackened pieces of cooked meat with a charred texture sitting inside a creamy white frying pan. The meat has a rough, crispy surface with some reddish-brown areas and small bits of burnt seasoning around them. The pan itself has some oil spots and brown stains, giving it a well-used look. The frying pan is on a white marbled surface with soft natural light casting shadows in the background. photo taken with an iphone --ar 4:5 --v 7

Getting this burger just right is all about using a handful of simple, flavorful ingredients that work together to create deep, smoky, and tangy layers. Each item brings its own magic, whether it’s the tender oyster mushrooms soaking up a bold marinade or the pickled jalapeños adding that vibrant zing to every bite.

Dark soy sauce: Adds a rich, umami depth and saltiness for intense flavor; feel free to reduce it if you prefer less salt.
Liquid smoke: Brings that irresistible smoky aroma that mimics a perfect grilled burger patty.
Smoked paprika: Enhances smokiness with a subtle earthy sweetness.
Garlic powder: Provides a warm and savory undercurrent that rounds out the flavors.
Onion powder: Adds sweetness and complexity without overpowering.
Olive oil: Helps the marinade coat the mushrooms evenly and keeps them juicy during cooking.
Oregano: Offers a herbaceous touch that brightens the overall flavor profile.
Lime juice: Introduces a splash of acidity to balance the smoky and sweet notes.
Maple syrup: Adds a gentle sweetness to contrast the heat and smokiness perfectly.
Oyster mushrooms: The star ingredient, with meaty texture perfect for crushing and searing.
Brioche buns: Soft, buttery, and slightly sweet, ideal for holding all the flavors together.
American cheese slices: Melts beautifully over the patties, creating a creamy, nostalgic burger vibe.
Pickled jalapeños: Packs that punch of spice and tang that wakes up every bite.

How to Make Vegetarian Smashed Mushroom Burger with Pickled Jalapeños Recipe

Step 1: Make the Marinade

Start by mixing the dark soy sauce, liquid smoke, olive oil, smoked paprika, garlic powder, onion powder, and oregano in a bowl. This marinade is the secret behind the burger’s smoky, savory flavor, so make sure everything is well combined to coat the mushrooms evenly.

Step 2: Marinate the Mushrooms

Toss your oyster mushrooms in the marinade and let them soak up those flavors for at least 10 to 15 minutes. This step is essential because the mushrooms absorb the smoky, salty punch and get juicy, which makes all the difference when seared.

Step 3: Preheat the Pan

While the mushrooms marinate, heat a cast iron skillet or a heavy-bottomed pan over high heat. Adding a little oil will prevent sticking and help you get that perfect sear that locks in flavor and texture.

Step 4: Sear and Smash the Mushrooms

Place the mushrooms gill-side down and immediately press each one flat with a heavy spatula or pan. Hold for 20 to 30 seconds without moving to build a beautiful crust. Let them sear for 2 to 3 minutes until golden brown, then flip and repeat. Keep flipping until both sides are perfectly seared and irresistibly crispy on the edges.

Step 5: Add Cheese

Once your mushrooms are nearly done, flip them over and top each patty with slices of American cheese. Cover the pan with a lid briefly so the cheese melts into gooey goodness that stretches with every bite.

Step 6: Toast and Assemble

Toast your brioche buns lightly until golden and warm. Spread sriracha mayo on the bottom bun for creamy heat, add your cheesy smashed mushroom patty, pile on plenty of pickled jalapeños for that spicy brightness, then crown with the top bun. This assembly promises the perfect bite of smoky, creamy, spicy, and soft all at once.

How to Serve Vegetarian Smashed Mushroom Burger with Pickled Jalapeños Recipe

A close-up view of a cheeseburger held by a woman's hand, showing three main layers inside a lightly toasted bun: the top bun is pale brown and soft, below that is a layer of melted yellow cheese with a smooth texture, and underneath is a thick, dark grilled meat patty with a rough, slightly charred surface. The bottom bun is golden brown and slightly toasted. The burger is held over a white leaf-shaped plate, all on a white marbled background. photo taken with an iphone --ar 4:5 --v 7

Garnishes

To elevate your burger even more, consider adding fresh garnishes like crisp lettuce, ripe tomato slices, or thinly sliced red onions. These add refreshing crunch and balance the richness of the cheese and mushrooms without overpowering the pickled jalapeños’ heat.

Side Dishes

This burger shines alongside classic fries or onion rings, but don’t hesitate to mix things up with a zesty coleslaw or grilled corn on the cob. Each side offers a new texture or flavor contrast that complements the vegetarian smashed mushroom burger beautifully.

Creative Ways to Present

For a fun twist, serve mini sliders with toothpicks for casual gatherings or stack your burger with multiple smashed mushroom patties to create a towering delight that’s sure to impress. Wrapping the finished burger in parchment paper gives a rustic, approachable vibe perfect for picnics or on-the-go meals.

Make Ahead and Storage

Storing Leftovers

If you happen to have leftovers, store the mushroom patties and buns separately in airtight containers in the refrigerator. This prevents the buns from getting soggy and keeps the patties tender for up to 2 days.

Freezing

You can freeze the cooked mushroom patties by placing them on a parchment-lined tray in the freezer until frozen solid, then transfer to a freezer-safe bag. They last up to 1 month and thaw quickly in the fridge for future meals.

Reheating

To reheat, warm the patties gently in a skillet over medium heat to maintain their seared texture. Toast the buns separately and melt cheese fresh if needed. This method keeps everything tasting fresh and delicious.

FAQs

Can I use other mushroom varieties instead of oyster mushrooms?

Absolutely! While oyster mushrooms have a great texture for smashing and searing, you can also try cremini or shiitake mushrooms. Just keep in mind that cooking times and texture might vary slightly.

Is this recipe spicy because of the pickled jalapeños?

The pickled jalapeños add a noticeable but balanced kick of heat. If you prefer less spice, you can reduce the amount or substitute with milder pickled peppers or simply omit them.

Can I make this burger vegan?

Definitely! Swap the American cheese for your favorite vegan cheese slices and use vegan mayonnaise in place of sriracha mayo to keep it completely plant-based without losing any flavor.

How can I make the marinade less salty?

Simply reduce the soy sauce to 1 tablespoon or use a low-sodium soy sauce alternative. The other ingredients will still provide plenty of flavor, keeping your burger tasty without overwhelming saltiness.

What’s the best way to press the mushrooms when smashing them?

Use a sturdy, flat spatula or the bottom of a small heavy pan to press down firmly but gently, ensuring the mushrooms stay in contact with the heat for an even, crispy sear without breaking apart.

Final Thoughts

This Vegetarian Smashed Mushroom Burger with Pickled Jalapeños Recipe is a delightful way to enjoy a satisfying, smoky burger that’s impossible to resist. Whether you’re a longtime vegetarian or simply looking to shake up your dinner routine, this recipe offers bold flavors, juicy textures, and just the right amount of spicy kick. Give it a try—you might just find your new favorite burger that everyone will be asking you to make again and again!