Copycat Five Guys Veggie Sandwich Recipe

A loaded veggie sandwich featuring grilled mushrooms, green peppers, and onions nestled in a soft sesame seed bun with melted American cheese and classic Five Guys toppings.
Difficulty:
Beginner
Prep Time:
15 mins
Cook Time:
10 mins
Serves:
2 sandwiches
An overhead shot of the Five Guys Veggie Sandwich cut diagonally, revealing layers of caramelized mushrooms, charred green peppers, and sweet onions nestled between melted American cheese. The toasted sesame seed bun has a golden-brown exterior while staying soft inside, captured in natural window lighting that highlights the gleaming vegetables and melty cheese. Fresh lettuce, tomato slices, and pickle chips add vibrant color contrast, while a dollop of mayo and ketchup peek out from the edges. The sandwich sits on a red and white checkered wrapper reminiscent of the restaurant experience, with a small pile of seasoned fries visible in the corner of the frame.

Ingredients

<ul class="ingredients-main-list"><li class="ingredients-single-item">2 sesame seed burger buns</li><li class="ingredients-single-item">4 slices American cheese (or dairy-free alternative)</li><li class="ingredients-single-item">150g button mushrooms, sliced</li><li class="ingredients-single-item">1 green bell pepper, sliced</li><li class="ingredients-single-item">1 medium onion, thinly sliced</li><li class="ingredients-single-item">1 tbsp vegetable oil</li><li class="ingredients-single-item">1/2 tsp salt</li><li class="ingredients-single-item">1/4 tsp black pepper</li><li class="ingredients-single-item">2 tbsp mayonnaise</li><li class="ingredients-single-item">2 tbsp ketchup</li><li class="ingredients-single-item">1 tbsp mustard (optional)</li><li class="ingredients-single-item">4 lettuce leaves</li><li class="ingredients-single-item">1 tomato, sliced</li><li class="ingredients-single-item">4 pickle slices</li><li class="ingredients-single-item">Optional: jalapeño slices, hot sauce, barbecue sauce</li></ul>

Equipment

<ul class="equipment-main-list"><li class="equipment-single-item">Non-stick frying pan</li><li class="equipment-single-item">Spatula</li><li class="equipment-single-item">Baking sheet</li></ul>
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Directions

<ol class="no-list-style"><li class="MethodStepper"><h4 class="step-title">Step 1</h4>Preheat your oven to 180°C (350°F). Place your sesame seed buns on a baking sheet, cut side up, ready to toast later.</li><li class="MethodStepper"><h4 class="step-title">Step 2</h4>Heat the vegetable oil in a non-stick frying pan over medium-high heat. Add the sliced mushrooms and cook for about 3-4 minutes until they begin to release their moisture and start to brown. Mushrooms need space to properly brown rather than steam, so avoid overcrowding the pan.</li><li class="MethodStepper"><h4 class="step-title">Step 3</h4>Add the sliced green peppers and onions to the pan with the mushrooms. Season with salt and pepper. Sauté for another 5-6 minutes, stirring occasionally, until the vegetables are tender and slightly caramelized. The slow caramelization process creates the signature Five Guys flavor profile by bringing out the natural sweetness of the vegetables.</li><li class="MethodStepper"><h4 class="step-title">Step 4</h4>While the vegetables are cooking, place the buns in the preheated oven for 2-3 minutes until lightly toasted. The toasting step is crucial for texture contrast and prevents the bun from becoming soggy when the juicy vegetables and condiments are added.</li><li class="MethodStepper"><h4 class="step-title">Step 5</h4>Remove the toasted buns from the oven. Place two slices of American cheese on the bottom half of each bun. The residual heat from the bun will help melt the cheese slightly, creating that perfect gooey foundation for your vegetables.</li><li class="MethodStepper"><h4 class="step-title">Step 6</h4>Divide the sautéed vegetable mixture evenly between the two sandwiches, placing them directly on top of the cheese slices. The hot vegetables will further melt the cheese, creating that signature Five Guys cheese-vegetable integration.</li><li class="MethodStepper"><h4 class="step-title">Step 7</h4>Spread mayonnaise, ketchup, and mustard (if using) on the top half of each bun. Layer with fresh lettuce, tomato slices, and pickles. Add any optional toppings like jalapeños or additional sauces according to your preference.</li><li class="MethodStepper"><h4 class="step-title">Step 8</h4>Carefully close the sandwiches, pressing down gently to compact all ingredients. If desired, wrap the bottom half in foil or parchment paper (like they do at Five Guys) to make eating easier and keep all the delicious components together. Serve immediately while the vegetables are still warm and the cheese is melty.</li></ol>

Nutrition Facts (per serving)

🍽️ Serving Size: 1 sandwich
🔥 Calories: 385 calories
🥑 Fat: 18 g
🧈 Saturated Fat: 7 g
🍞 Carbohydrates: 42 g
🍭 Sugar: 8 g
🍗 Protein: 12 g
🫀 Cholesterol: 30 mg
🧂 Sodium: 620 mg

Chef’s Notes

A few helpful details for making this recipe.

Can I make this vegetarian sandwich recipe vegan?

Absolutely! Simply replace the American cheese with your favourite vegan cheese alternative and use plant-based mayonnaise. The vegetables and other toppings are already vegan-friendly, making this an easy recipe to adapt while maintaining the authentic Five Guys experience.

What's the secret to getting perfectly caramelized vegetables for a restaurant-quality veggie sandwich?

The secret is patience and proper heat management. Cook mushrooms first until they release moisture, then add peppers and onions. Don't overcrowd the pan, use medium-high heat, and allow vegetables time to develop golden edges. Season properly and stir occasionally rather than constantly.

Which toppings work best with a grilled vegetable sandwich?

Classic toppings include lettuce, tomato, and pickles for freshness and crunch. Creamy elements like mayonnaise balance the sandwich, while ketchup and mustard add tanginess. For customisation, consider jalapeños for heat, avocado for creaminess, or crispy onions for extra texture.

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