Roasted Mushroom Sandwich with Horseradish Aioli Recipe

Introduction

This roasted mushroom sandwich with horseradish aioli is a flavorful and satisfying option for a hearty lunch or light dinner. Featuring golden, seasoned mushrooms, creamy havarti cheese, and a zesty aioli, it’s a perfect blend of savory and fresh flavors that will impress any sandwich lover.

Ingredients

• 16 ounces sliced mushrooms (portobello or white button mushrooms)
• 2 tablespoons avocado oil
• 2 tablespoons Cajun seasoning (adjust salt as needed)
• Salt and pepper to taste
• 1/2 cup mayo
• 1 small clove garlic, grated (or half a clove)
• 1-2 teaspoons horseradish sauce, to taste (e.g., Boar’s Head)
• 1-2 teaspoons lemon juice, to taste
• Salt, to taste
• Big chunk of bread you love (such as caramelized onion focaccia)
• Pesto rosso (optional, as a second sauce)
• Havarti cheese slices
• Arugula tossed with olive oil and lemon

Instructions

1. Step 1: Preheat your oven to 450°F (230°C). Toss the sliced mushrooms with avocado oil and Cajun seasoning on a sheet pan until they’re evenly coated. Spread them out in a single layer.
2. Step 2: Roast the mushrooms for 20 to 25 minutes, stirring once or twice, until they become golden brown and caramelized.
3. Step 3: While the mushrooms roast, prepare the horseradish aioli by mixing mayo, grated garlic, horseradish sauce, lemon juice, and salt in a bowl. Adjust seasoning to your taste.
4. Step 4: Toast your bread on the same pan for the last few minutes of mushroom roasting to warm and crisp it slightly.
5. Step 5: Split the toasted bread and spread pesto rosso on one side, if using. Layer the roasted mushrooms and Havarti cheese slices on the bread. If you prefer melted cheese, return the assembled sandwich to the oven for about a minute.
6. Step 6: Add a handful of arugula tossed with olive oil and lemon on top of the cheese. Spread the horseradish aioli on the top piece of bread, then close the sandwich and enjoy!

Tips & Variations

• Use different mushroom varieties like cremini or shiitake for unique flavors and textures.
• If you don’t have horseradish sauce, a bit of Dijon mustard adds a nice kick to the aioli.
• Swap Havarti for Swiss, mozzarella, or provolone for a different cheese experience.
• Adding sliced tomatoes or pickled onions can add brightness and contrast.
• For a vegan option, use vegan mayo and cheese alternatives.

Storage

Store leftover roasted mushrooms and aioli separately in airtight containers in the refrigerator for up to 3 days. Assemble the sandwich fresh to avoid soggy bread. Reheat mushrooms gently in a skillet or microwave before assembling, and toast bread just before serving.

How to Serve

Serve this delicious recipe with your favorite sides.

FAQs

Can I use dried mushrooms instead of fresh?

Fresh mushrooms are best for roasting because they caramelize and retain texture. If using dried mushrooms, rehydrate them first and adjust cooking time accordingly, but the flavor and texture will differ.

Is horseradish sauce very spicy?

Horseradish sauce has a sharp, tangy heat but it’s usually milder than hot mustard or chili peppers. You can adjust the amount to suit your spice preference or omit it if you prefer a milder sandwich.

Roasted Mushroom Sandwich with Horseradish Aioli Recipe

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4.8 from 124 reviews

This Roasted Mushroom Sandwich with Horseradish Aioli is a flavorful vegetarian delight featuring tender, seasoned mushrooms roasted to perfection, layered with creamy Havarti cheese, zesty horseradish aioli, and fresh arugula on your favorite artisan bread. The sandwich balances smoky, tangy, and fresh flavors, making it a satisfying meal for lunch or dinner.

• Author: Clara
• Prep Time: 10 minutes
• Cook Time: 25 minutes
• Total Time: 35 minutes
• Yield: 2 sandwiches 1x
• Category: Sandwich
• Method: Roasting
• Cuisine: American
• Diet: Vegetarian

Ingredients

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Mushrooms and Seasoning

• 16 ounces sliced mushrooms (portobello or white button mushrooms)
• 2 tablespoons avocado oil
• 2 tablespoons Cajun seasoning (adjust salt level depending on brand)
• Salt and pepper to taste

Horseradish Aioli

• 1/2 cup mayonnaise
• 1 small clove garlic, grated (about half a clove is enough)
• 1–2 teaspoons horseradish sauce, to taste (e.g., Boar’s Head)
• 1–2 teaspoons lemon juice, to taste
• Salt to taste

Assembly

• Big chunk of bread you love (e.g., caramelized onion focaccia)
• Pesto rosso (optional, for spreading)
• Havarti cheese slices
• Arugula tossed with olive oil and lemon juice

Instructions

1. Roast the Mushrooms: Preheat your oven to 450°F (232°C). Toss the sliced mushrooms with avocado oil and Cajun seasoning on a sheet pan until well coated. Spread them out evenly to ensure proper roasting. Roast in the oven for 20-25 minutes until the mushrooms are golden brown and tender.
2. Make the Horseradish Aioli: While mushrooms are roasting, combine mayonnaise, grated garlic, horseradish sauce, lemon juice, and salt in a bowl. Mix well until smooth. Taste and adjust seasoning with additional horseradish, lemon juice, or salt as desired.
3. Toast the Bread: When mushrooms are almost done, toast your chosen bread slices briefly in the oven on the same pan to absorb some mushroom flavor and get a nice crust.
4. Assemble the Sandwich: Split the toasted bread and spread pesto rosso on the bottom half if using. Layer the roasted mushrooms evenly over the spread. Top the mushrooms with Havarti cheese slices; optionally place the sandwich back in the oven for a minute to melt the cheese. Add a handful of arugula tossed with olive oil and lemon juice on top. Spread the horseradish aioli on the top half of the bread and close the sandwich. Serve immediately for the best flavor and texture.

Notes

• Adjust the amount of Cajun seasoning to control saltiness as some blends vary in salt content.
• To enhance melting, place the assembled sandwich under a broiler for 1-2 minutes but watch carefully to avoid burning.
• Pesto rosso adds a nice smoky and tangy layer but can be omitted for a lighter sandwich.
• This sandwich is vegetarian but not vegan due to mayo and cheese.
• Use fresh mushrooms for best flavor; portobello will be meatier while white button mushrooms are milder.

Keywords: mushroom sandwich, roasted mushrooms, horseradish aioli, vegetarian sandwich, Havarti cheese sandwich, easy lunch recipe