Roasted Mushroom Sandwich with Horseradish Aioli Recipe
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.
- 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
Scale
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
- 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.
- 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.
- 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.
- 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
