Layers of roasty mushrooms, havarti, lemony arugula, and an easy homemade horseradish aioli make this mushroom sandwich a WINNER. A saucy, salty, hefty masterpiece!
16 ounces sliced mushrooms (portobello or white button mushrooms)
2 tablespoons avocado oil
2 tablespoons Cajun seasoning (if it has salt in it, you may want to add less of it just to make sure the mushrooms don’t get too salty – every brand is different)
salt and pepper to taste
1/2 cup mayo
1 small clove garlic, grated (even half a clove is plenty)
1-2 teaspoons horseradish sauce, to taste (I use Boar’s Head)
1-2 teaspoons lemon juice, to taste
salt, to taste
Big honking chunk of bread that you really love (I like Trader Joe’s caramelized onion focaccia for this)
Pesto rosso (optional as a second sauce)
Havarti cheese slices
Arugula tossed with olive oil and lemon
Categories
Sandwich
Cuisine
American
Steps
Preheat the oven to 450 degrees. Toss the sliced mushrooms with the avocado oil and the seasoning on a sheet pan until well-combined. Roast for 20-25 minutes, until golden brown.
Mix all the sauce ingredients in a bowl until well-combined. Taste and season.
Toast the bread for the last few minutes on the pan with the mushrooms. Split the bread, spread with pesto rosso, roasty mushrooms, havarti (pop it in the oven again for a minute if you want it to melt), arugula, and the top piece of bread shmeared with the horseradish sauce. OH MY WORD can you even? This is so good.
Nutitrion
Calories: 439 calories
Carbohydrates: 10.6 g
Protein: 9 g
Fat: 41.3 g
Saturated Fat: 8.5 g
Trans Fat: 0.1 g
Cholesterol: 24.7 mg
Sodium: 809.9 mg
Sugar: 3.2 g
Reviews
Margaret Hill on 2023-12-12 (5 stars): Made these tonight, yum yum yum!
DO NOT SKIP THE AIOLI (and the pesto Rosso took this sandwich over the top) whole family loved them :)
Sarah on 2023-12-13 (5 stars): This is so incredibly good! I made it twice in three days. My husband asked where I got the recipe (which he never does).
Liz on 2023-12-14 (5 stars): I made this after watching the reel, and it was sooo delicious. The flavors go so perfectly together, and I can’t wait to make it again!
Annie M Pellegrini on 2023-12-16 (5 stars): This sandwich is outstanding. Each component - the two sauces, the roasted mushrooms and the dressed lettuce - come together for a very tasty and satisfying experience. I made this for my husband and he thought I had bought it from a deli ... lol! This recipe made it into our rotation. Very grateful.
Susan on 2023-12-18 (5 stars): Surprisingly flavorful for how little effect it is to make.
Megan on 2023-12-20 (5 stars): Love this recipe!!! Definitely going to be using the horseradish aioli with other meals as well. Thank you!
williams on 2023-12-21 (5 stars): After viewing the reel, I recreated this dish, and it turned out incredibly delicious. The flavors complement each other perfectly, and I'm eagerly anticipating making it again!
Joy on 2024-01-03 (5 stars): Made this dish tonight. It comes together easily and most of the time spent was hands-off, a huge bonus. To add a little protein, I sliced a block of tofu into strips and seasoned with cajun seasoning, then roasted it with the mushrooms. I didn't use the suggested pesto rosso or fancy foccaccia (just our regular bread), but felt the sandwich worked fine without both. Very enjoyable, and something we will make again.
spike on 2026-01-31 (5 stars): made this amazing dish tonight, very enjoyable ,sure i will make this again
Alphabet on 2024-01-04 (5 stars): Such an incredible burger!! AND those caramelized onions are absolutely amazing!!
Jessica on 2024-01-08 (5 stars): Made this tonight and it’s an easy + super delicious and flavorful meal! All of the ingredients shine through and taste incredible melted together!
Doodle Baseball on 2024-01-10 (5 stars): This is the best Grilled Mushroom Sandwich with Horseradish Aioli I've ever made. I will make this dish for my family following your recipe. I hope it will be delicious
Ellen on 2024-01-11 (5 stars): What an excellent recipe, absolutely delicious. You can't skip the pesto rosso, the aioli or the arugula. The flavors just pair so perfectly with the mushrooms. Thank you!!
wordle unlimited on 2024-01-11 (5 stars): That's amazing! I tried the recipe you shared and it worked! Everyone praised them very well. Thank you for sharing with me and everyone.
Danielle Davis on 2024-02-12 (5 stars): I used closed white mushrooms and had some chestnut mushrooms left over so used both and it was delicious
Khava on 2024-01-20 (5 stars): This was DELICIOUS! I doubled the mushrooms because I love them. It didn’t take long at all and the payoff of was tenfold. I did use half the recommended amount of seasoning due to the salty factor of my Cajun seasoning and it was still great. Thank you POY!
Lu on 2024-01-29 (5 stars): 10/10 - my husband has requested that this be part of our regular meal rotation!
Lynne on 2024-01-30 (2 stars): Reading all of the other positive comments I really wanted this to be a favourite. It was easy to make but I found the pesto, cajun seasoning, lemon dressing, and aioli to be flavour overload on this sandwich.
I have tried many recipes from this site with great success and look forward to many more!!
Danielle Davis on 2024-02-12 (5 stars): This was so delicious! "Meaty", saucy and definitely made a few people jealous at lunch. Lol. My favourite vegetarian lunch so far!
Tiffany on 2024-03-24 (5 stars): This was an amazing recipe! My husband and I kept saying “these are so good!” the whole time we ate them. Extra bonus that they were easy to make. Will definitely make these again!
