Balsamic Mushroom + Caramelized Onion Cheddar Mac ‘n Cheese {vegetarian}

I like to spend about a day each weekend making food for the upcoming week. It serves a dual purpose for me. 1. I have no energy during the week to make food. If I don’t have food on hand I will end up eating whatever I can get my hands on, which sometime means eating stovetop popcorn for dinner. 2. Cooking/baking is cathartic and a creative outlet. I love the reaction people have when I feed them something super yummy.

I’m heading back up to Portland next weekend and have a bunch of food in my fridge that needs to be used up. The other day my dad and I were out to eat at a local eatery that will remain nameless. He ordered mushroom mac and cheese, which we laughed about when we saw it on the specials board because he had just literally been saying to me: do you think mushrooms would work well in mac and cheese?

While he was eating his disappointing lunch, he suggested that I could make a better mushroom mac at home. Challenge accepted! And perfect timing because I had some mushrooms in the fridge and plenty of cheese pasta choices to choose from. But where to start when it comes to mushroom mac? There are so many mushroom types out there but I needed a recipe that used “normal” mushrooms. My dad’s restaurant mac and cheese was made with shiitake mushrooms. I have a love-hate relationship with shiitake mushrooms. I want to love them but just don’t.

In my search for a recipe using button or cremini mushrooms, I came across one I found intriguing at Whole and Heavenly Oven. It wasn’t just about mushrooms at all. Caramelized onions were featured and so was balsamic vinegar. While I happen to like balsamic vinegar, I know it’s a polarizing taste. Sis doesn’t like, and I couldn’t remember how dad felt about it. Even so I’m relatively food adventurous so I thought I would give it a try.

And I’m glad I did. It’s a bit of a different flavor than what you might be used to in mac and cheese. It’s both savory from the cheese and sweet from the balsamic vinegar. And it’s perfectly creamy.

For this batch of mac and cheese, I used Kamut wheat elbow pasta. Kamut is an ancient grain variety of pasta that’s higher in protein than regular wheat pasta and is still 100% whole grain. I’ve been wanting to try Kamut pasta for mooooonths but stopped eating wheat pasta when I went gluten-free. Bonus: Kamut wheat pasta also better for those who have gluten sensitivities, which is a bonus for me because my doctor still thinks I’m not eating gluten. (Read more about Kamut pasta here.)


  • 4 T. plus 4 T. butter, divided
  • 1 medium onion, thinly sliced
  • 8 oz button or cremini mushrooms, thinly sliced
  • 2 cloves garlic, minced
  • ½ c. balsamic vinegar
  • ¼ c. flour
  • ½ c. half and half cream
  • 1 ½ c heavy cream
  • 16 oz sharp cheddar cheese, shredded
  • 16 oz elbow pasta, cooked according to package instructions
  • Salt and pepper to taste


  1. In a large cast iron skillet over medium-low or low heat, melt half the butter. Add onions and plenty of salt and saute, stirring occasionally until onions are a deep golden brown and tender, about 20 to 25 minutes.
  2. Meanwhile start cooking your noodles according to package directions to get an al dente noodle. Drain and reserve about 1 cup of the pasta water.
  3. Push onions to the side of the pan. Add the mushrooms and sprinkle some salt over the mushrooms. The mushrooms should shrink and release water almost immediately. Cook the water out of the pan. Add garlic and balsamic vinegar and turn the heat up to medium. Cook until the balsamic has reduced and is no longer liquidy-5 to 10 minutes. Scrape most of the onion mixture into a bowl and set aside. Spread the remaining onion mixture across the pan. (You should not have much in the bottom of the pan – it should basically look like you’re garnishing the pan.)
  4. In the empty pasta pot, add remaining butter and melt over low heat. Add flour and whisk until smooth. Allow the mixture to cook for about another minute or two until golden brown and then slowly add the creams. Whisk to ensure the mixture is smooth. Bring to a simmer over medium heat until sauce is bubbly and thickened.
  5. Remove sauce from heat and whisk in half the cheese until melted. Add cooked pasta and stir until evenly combined. If necessary, add some pasta water. Season with salt and pepper to taste, if necessary. I didn’t need to add salt to the mixture and did not add forgot to add pepper.
  6. Pour half the mac and cheese mixture back into the cast-iron pan. Top with half of the remaining cheese and half of the onion mixture. Repeat.
  7. Bake mac ‘n’ cheese at 375F 15-20 minutes or until bubbly and golden brown. Let sit for 5 minutes or so before serving.

Recipe rating: 

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