Prep Time: 35 minutes
Cook Time: 25 minutes
Total Time: 1 hour
Servings: 4 burgers

Ingredients

For the Mushroom Patties

• 4 large portobello mushroom caps (about 4 inches wide)
• 1 tablespoon olive oil
• 1 teaspoon kosher salt
• ½ teaspoon black pepper

Cheese Filling

• 1 cup shredded Muenster cheese
• 1 cup shredded sharp cheddar cheese
• 1 tablespoon all-purpose flour
• 1 egg yolk
• ½ teaspoon onion powder
• ¼ teaspoon garlic powder
• ⅛ teaspoon cayenne pepper (optional)
• Pinch of salt

Crispy Coating

• 1 cup all-purpose flour
• 2 large eggs, beaten
• 2 cups panko breadcrumbs
• 1 teaspoon garlic powder
• 1 teaspoon onion powder
• ½ teaspoon paprika
• ½ teaspoon salt
• ¼ teaspoon black pepper

Shack-Style Sauce

• ½ cup mayonnaise
• 1 tablespoon Dijon mustard
• 1 tablespoon ketchup
• 1 teaspoon pickle juice
• ¼ teaspoon cayenne pepper
• Pinch of salt

For Assembly

• 4 potato buns or brioche buns
• 4 lettuce leaves
• 8 slices tomato
• Butter for toasting buns

Equipment

• Baking sheet
• Mixing bowls
• Deep skillet or Dutch oven
• Wire rack
• Tongs
• Kitchen thermometer

Instructions

Step 1: Prepare the Mushroom Caps

Clean the portobello mushrooms with a damp paper towel.

Remove the stems and gently scrape out the dark gills from the underside.

Brush both sides with olive oil and season with salt and pepper.

Place mushrooms on a baking sheet.

Bake at 375°F (190°C) for 15–20 minutes until slightly softened.

Allow them to cool completely.

Step 2: Make the Cheese Filling

In a bowl, combine:

• Muenster cheese
• Cheddar cheese
• Flour
• Egg yolk
• Onion powder
• Garlic powder
• Cayenne pepper
• Salt

Mix until a thick cheese mixture forms.

Divide the cheese mixture into four portions.

Shape each portion into a small disk slightly smaller than the mushroom caps.

Step 3: Stuff the Mushrooms

Slice each cooled mushroom cap horizontally into two thin halves.

Place one cheese disk between two mushroom halves.

Press gently around the edges to seal the mushroom sandwich.

Repeat with remaining mushrooms.

Chill the stuffed mushrooms for 15–20 minutes to help them hold their shape.

Step 4: Prepare the Coating

Set up three bowls:

Bowl 1:

• Flour

Bowl 2:

• Beaten eggs

Bowl 3:

• Panko breadcrumbs
• Garlic powder
• Onion powder
• Paprika
• Salt
• Pepper

Dip each stuffed mushroom:

1. Coat in flour.
2. Dip into beaten egg.
3. Cover completely with seasoned panko.

For an extra-crispy crust, repeat the egg and panko coating a second time.

Step 5: Fry the Mushroom Patties

Heat about 2 inches of oil in a heavy skillet to 350°F (175°C).

Carefully fry the mushroom patties for about 2–3 minutes per side until golden brown and crispy.

Transfer to a wire rack to drain.

Avoid placing them directly on paper towels, which can soften the crust.

Step 6: Make the Shack Sauce

Whisk together:

• Mayonnaise
• Dijon mustard
• Ketchup
• Pickle juice
• Cayenne pepper
• Salt

Refrigerate until ready to assemble.

Step 7: Toast the Buns

Butter the inside of the potato buns.

Toast in a skillet for 1–2 minutes until lightly golden.

Step 8: Assemble the ‘Shroom Burgers

Build each burger:

1. Bottom toasted bun
2. Shack-style sauce
3. Crispy cheese-filled mushroom
4. Lettuce
5. Tomato slices
6. More sauce
7. Top bun

Serve immediately while the mushroom patty is hot and the cheese is melted.

Serving Suggestions

These ‘Shroom Burgers pair perfectly with:

• Crispy French fries
• Cheese fries
• Onion rings
• Sweet potato fries
• Pickles
• Milkshakes
• Fresh lemonade
• Side salad

Storage

Mushroom Patties: Store cooked patties in an airtight container in the refrigerator for up to 3 days.

Reheating: Reheat in an air fryer at 375°F (190°C) for 5–7 minutes or bake until crispy.

Sauce: Store separately in the refrigerator for up to 1 week.

For the best texture, assemble burgers fresh rather than storing fully assembled sandwiches.

Tips for the Best Copycat Shake Shack ‘Shroom Burger

• Choose large, firm portobello mushrooms so they are easier to stuff.
• Roast mushrooms before stuffing to remove excess moisture.
• Chill the stuffed mushrooms before breading to prevent the cheese from leaking.
• Use panko breadcrumbs for a lighter, crunchier coating.
• Double-coat the mushrooms for a thicker restaurant-style crust.
• Toasting the bun adds flavor and prevents sogginess.
• Serve immediately after frying for the best crispy texture.

Recipe Notes

• Muenster and cheddar create the classic creamy, melty filling, but you can substitute with Monterey Jack, provolone, or mozzarella.
• For an air fryer version, spray breaded mushroom patties lightly with oil and cook at 375°F (190°C) until golden and crisp.
• Add caramelized onions or pickles for extra flavor.
• This recipe can be prepared ahead by stuffing and breading the mushrooms, then refrigerating them until ready to fry.
• The ‘Shroom Burger is naturally vegetarian, making it a great option for meat-free burger nights.