What if I told you that this was the best thing I’ve eaten in weeks?

15 Minute Mushroom Melts with Mustard Aioli I howsweeteats.com

I mean, I know I’m dramatic and all and according to some people, use the term “the best” way too loosely. And I’ve eaten many things over the course of the last few weeks, including but not limited to my fair share of burgers, multiple sushi rolls, pizzas upon pizzas and wine.

I think I had wine for dinner one night, actually. It happens.

15 Minute Mushroom Melts with Mustard Aioli I howsweeteats.com

But yeah. The best thing out of all of those things has been a good ol’ slice of bread covered in mushrooms and cheese. AND MUSTARD AIOLI.

This is my absolute new favorite spread. I want to cover all the things in mustard aioli. It’s INSANE. So insane that I can’t stop using all caps. It’s necessary. And all the real writers around the world just gave the biggest collective, simultaneous eye roll. It’s just that it is so flavorful.

It has pretty much changed my life.

15 Minute Mushroom Melts with Mustard Aioli I howsweeteats.com

These are slightly similar to those red wine roasted mushroom and goat cheese toasts I shared a few weeks ago, except, um… they are totally different. Back then I wasn’t aware of this elixir of the gods, otherwise known as the mustard aioli. Seriously, if you could bottle the tears of baby cherubs this is probably what they would taste like.

Can you tell I’m in love?

15 Minute Mushroom Melts with Mustard Aioli I howsweeteats.com

I know some of you may not be down with eating a raw egg yolk, so if you’re young or old or with child or just not thrilled with that idea, Bobby Flay has one without. I didn’t try it, but still wanted to share in case you’re a bit skeeved out. I’m sure there are others out there, so share below if you’d like.

In the meantime, you might want to try this for breakfast or lunch or dinner or a snack.

Or e). all of the above.

15 Minute Mushroom Melts with Mustard Aioli I howsweeteats.com

Mushroom Melts with Mustard Aioli

5 from 2 votes
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  • 8 ounces sliced cremini mushrooms
  • 1 tablespoon unsalted butter
  • 1 tablespoon olive oil
  • 3 garlic cloves, minced or pressed
  • a pinch of salt + pepper
  • 4 slices whole grain bread
  • 6 ounces fontina cheese, freshly grated

mustard aioli


  • Heat a large skillet over medium-low heat. Add olive oil and butter, then add mushrooms and toss well to coat. Cover and cook for 8-10 minutes, until soft and juicy, stirring once or twice during cooking time.
  • While mushrooms are cooking, whisk together dijon mustard, egg yolk and lemon juice in a large bowl until combined. Slowly stream in olive oil while continuously whisking until the mixture emulsifies and comes together completely. Whisk in whole grain mustard and horseradish, then taste and season with salt and pepper as desired.
  • Heat the broiler on your oven to the highest setting, placing an over rack directly underneath. Lay four slices of whole grain bread on a baking sheet and pop under the broiler for 1-2 minutes, until golden. Remove and spread a layer of mustard aioli on top.
  • Remove the cover from the mushrooms and stir in the garlic, salt and pepper, cooking for one minute. Turn off heat, then distribute mushrooms evenly among the four slices of toast. Cover with grated cheese. Place back under the broiler for 1-2 minutes, until cheese is bubbly and slightly golden. Remove and serve immediately with extra mustard aioli on top.


[mustard aioli from martha]

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I appreciate you so much!

15 Minute Mushroom Melts with Mustard Aioli I howsweeteats.com

Yep. In love.