Quick and easy cheesy mushroom toast recipe! Sauteed mushrooms on toast with Maille Old Style Mustard, fresh thyme, and melted swiss cheese. A hearty, savory vegetarian meal.

This mushroom toast recipe is sponsored by Maille. All opinions are my own. Thank you for supporting the brands that support Rhubarbarians!
Hi, Rhubarbarians! Today's recipe is loaded with one of my favorite veggies: mushrooms. This mushroom toast is hearty, savory, full of umami, and can be served as an appetizer, snack, or even a full meal.
Mushroom toast is a very simple and easy to throw together meal, perfect for a hearty or lunch or light dinner.
Looking for more mushroom recipes?
Cauliflower quinoa burgers with mushrooms and onions
Cheese tortellini with caramelized onion sauce
Stacked ale mushrooms with arugula and goat cheese

Maille Old Style Mustard
A key ingredient to this simple mushroom toast is Maille old style mustard. I love the grainy texture and the intense flavor of this mustard. It compliments the earthiness of the mushrooms perfectly by adding some tang and acidity, and adds a whole new dimension to the flavor of simple mushrooms on toast!
Just a spoonful of this mustard goes a long way and can add so much flavor to your dressings or dishes.
More ways to add flavor with a spoonful of dijon mustard:
Pear and apple spinach salad with honey mustard dressing
Vegetarian white bean cassoulet

What is mushrooms on toast?
Mushrooms on toast is a simple dish from Britain. It is traditionally kept very simple, just sauteeing up some mushrooms and eating them atop toast. It's eaten as a filling snack or a light meal rather than an entree.
This mushroom toast is a bit different than the traditional British meal. I add lots of flavor with swiss cheese, dijon mustard, and fresh thyme. I also broil the mushrooms and cheese over the bread and toast the whole thing together.

How to make mushroom toast
Mushroom toast is amazingly simple, but loaded with flavor. Since there are so few ingredients, you'll want to choose very high quality produce and products. Very fresh baby bella or cremini mushrooms, rustic bread with a hearty crust, whole grain dijon mustard like Maille old style mustard, and aged swiss cheese.
Chop your mushrooms and garlic and heat up a frying pan. Melt the butter and sweat the mushrooms. Add the garlic and saute together until the mushrooms are very brown and starting to crisp.
Turn on the broiler and build your mushroom toast. Spread the mustard on the bread, top with a bit of cheese, top with mustard, then top with more cheese. Broil until the cheese is melted and starting to brown. Sprinkle with fresh thyme, salt, and pepper.


How to serve mushrooms on toast as an appetizer
Mushroom toast makes an amazing appetizer! Think: mushroom crostini.
Just replace the bread in this recipe with baguette slices. You should be able to make about 8 mushroom crostinis just using smaller slices of bread. All of the ingredients will stay the same.

How to make mushroom toast a full meal
These mushroom toasts are rather large, and 2 of them could easily fill you up. The recipe in itself is much like an open faced mushroom melt or warm open faced mushroom sandwich.
- Top with arugula to add some greens to the dish
- Add a layer of cannellini beans before adding the mushrooms.
- Top with an additional slice of bread to make a sandwich
- Add some walnuts to your sauteed mushrooms

Cheesy mushroom toast with Maille old style mustard and thyme recipe

Quick and easy cheesy mushroom toast recipe! Sauteed mushrooms on toast with mustard, fresh thyme, and melted swiss cheese. A hearty, savory vegetarian meal.
- 2 Tbsp butter
- 4 cups sliced baby bella or cremini mushrooms
- 3 cloves garlic, minced
- 2 slices thick rustic french bread
- 2 Tbsp Maille old style mustard
- 1 cup shredded swiss cheese
- 1 tsp fresh thyme leaves
- salt and pepper
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Melt the butter in a sauce pan over medium high heat. Add the mushrooms and sweat, stirring occasionally, about 5 minutes. Add the garlic and saute, stirring often, about 15 minutes until mushrooms are browned and all liquid has evaporated.
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Preheat the broiler. Spread the mustard evenly on one side of each piece of bread. Top each slice with a sprinkle of cheese. Evenly top with the mushrooms and then top each with another generous sprinkle of cheese. Broil until the cheese is melted and starting to brown, about 2 minutes.*
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To serve, sprinkle with fresh thyme and season with salt and pepper.
*You'll want to watch the cheese to make sure it doesn't burn under the broiler. Cook times will vary.
Year’s Supply of Maille Giveaway!
Thank you Maille for sponsoring this post! Thank you, Rhubarbarians, for supporting the brands that I love.
I hope you’ll give this cheesy mushroom toast a try! Snap a pic and give me a shout on social media! #Rhubarbarians #MyMaille
Trish
P.S. Want to see what I’m cooking up this week? Check out my Instagram stories! And don’t forget to join my FaceBook community of vegetarian cooks!
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LindaT
Quick question, do have a recommendation for a Swiss cheese substitute? I am really not a fan.
Trish Bozeman
You could use shredded mozzarella, cheddar, or even havarti! Any melty cheese that you like will taste great.
Susan
Making this for tonight’s dinner. Already salivating...🧑🏻🍳
Trish Bozeman
Yay! I'd love to know how it turns out!
Jessica
These were deeeeeeelish!
Anna
Just made this for the hubby and it was Deeeelish! Thank you for posting it! It will be made again and again and again.
Trish Bozeman
I'm so glad you love it, Anna! 🙂
Mary
This was delicious, everyone loved it! I just used regular Dijon as that's what i had, have used the Maille old style in the past, it's delicious, just not something the other members of the house like at this point.
Gloria
Well I do love mushrooms...and bread. What a great alternative to bruschetta or garlic bread. This would work as an appetizer, or a great side to pasta, salad or soup.