Onion, Mushroom & Thyme Tart.




Based on a friend’s recommendation, I added balsamic vinegar to this and it is amazing! I also added freshly grated Gruyère cheese at the very end. Oh my! If you want to add cheese, you can also add freshly grated Parmigiano-Reggiano. I hope you enjoy!! The recipe card has been updated below.



Original POST:

I recently attended one of Amy Pennington‘s cooking classes. .  her Croatian cooking class to be exact (will post the deets on this lovely class later!). Amy was so friendly, funny and warm and I absolutely loved watching her cook . .  I found this recipe on her blog the other night and immediately ran to the store to get some puff pastry to make this.


The onion, mushroom, and thyme tart is freaking delicious. Absolutely wonderful. + it’s so simple to make. + it incorporates my absolute FAVE thing I am currently addicted to: puff pastry. I have been switching between the Aussie Bakery brand and Pepperidge Farms puff pastry, honestly because these are the only two brands that are available at the grocery stores closest to me (only QFC carries the Aussie Bakery ones; you can find Pepperidge Farms pretty much anywhere). I have not looked at Trader Joe’s, PCC or Whole Foods yet but I’m told I need to purchase the good stuff. The all butter puff pastry dough. The frozen puff pastry dough that I think costs like $20. For as often as I bake and eat puff pastry, I can’t afford to buy the good stuff every time but you can bet I will be testing some recipes soon with the all butter puff pastry. I mean, how can I not? If you have a brand that you use all the time and love, please tell me about it! All butter all the time?


To my puff pastry lovin’ friends. You must try this recipe. You will thank me later. I hope you enjoy!


Onion, Mushroom & Thyme Tart
Prep time

Cook time

Total time


Recipe type: Appetizer or Main
Serves: 6-8

  • 3 tablespoons olive oil
  • 2 large yellow onions, cut into thin half moons
  • 2-3 cups sliced mushrooms, try to use cremini or baby portobello mushrooms
  • 1 teaspoon salt
  • 5 to 7 sprigs fresh thyme, leaves stripped and chopped
  • 2-3 teaspoons balsamic vinegar
  • 1-2 sheets frozen puff pastry, defrosted but kept cool (Note: Splurge on the all-butter puff pastry from Dufour or Aussie Bakery. Pepperidge Farm has too many ingredients–none of them butter–for us to feel good about. I got this from Amy!)
  • freshly grated cheese: like Parmigiano-Reggiano or Gruyère (optional but highly recommended if you’re feeling indulgent!)

  1. Heat the olive oil in a large sauté pan over medium heat. Add the onions and stir continuously until softened, about 8 to 10 minutes. Sprinkle in the salt, add the sliced mushrooms and continue stirring until the onions release their moisture and the pan becomes more and more dry. When this happens, add half of the thyme and the balsamic vinegar and reduce the heat to medium low. Cook the veggies, stirring occasionally, until caramelized and golden, about 20 -25 minutes or so. (If the onions start to brown, reduce the heat as low as your stove goes.) Remove from the heat and set aside.
  2. Preheat the oven to 350°F. Adjust the oven rack to the center position.
  3. Unfold the sheet/s of defrosted puff pastry on a parchment-lined baking sheet. I used 2 so that my tart would be a little larger and just attached the puff pastry dough; you can just use 1 sheet if desired. Fold all the edges over to create the pretty border around your tart. Top the center of the rolled out puff pastry evenly with the onion, mushrooms, thyme mixture.
  4. Bake the tart for about 25 to 35 minutes, until the pastry is golden brown and flaky. When there is about 2-3 minutes left, if you are adding the cheese, sprinkle on the freshly grated cheese and continue baking for the remaining time. Remove it from the oven, sprinkle the remaining thyme over the top, and let it cool for about 10 minutes before slicing and serving. (Any leftover tart can be kept at room temperature, lightly covered with parchment. Best to crisp it in an oven or toaster oven prior to serving again.)


Recipe adapted from Amy Pennington. I added the mushrooms because I simply LOVE them.






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30 Responses to "Onion, Mushroom & Thyme Tart."

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  1. Nancy @ gottagetbaked

    October 18, 2012 at 8:17 pm

    I’m going to make this gorgeous tart soon. I love puff pastry and mushrooms so this is a winning combination in my opinion, especially since it’s so simple to put together. I laughed when I read your tweet to Pepperidge Farms – you crack me up, woman! Hopefully they try to woo you back by giving you free stuff ;)

    • hipfoodiemom

      October 18, 2012 at 8:42 pm

      Haha! Thank you, Nancy! :) I was kinda just playing around. . but not really. . seriously, I don’t know what they have in Vancouver but spend a little extra and get the good puff pastry! :)

  2. Kim Bee

    October 19, 2012 at 12:44 am

    Dang woman, this is amazing. Love the photos. So inviting, just want to grab a slice through the screen.

    • hipfoodiemom

      October 19, 2012 at 4:27 am

      Haha, thank you, Kim!!! :) You just made my night with that comment! :) Thank you so much!

  3. Brandi @ TheHealthyFlavor.com

    October 19, 2012 at 6:54 am

    Beautiful Alice!! That looks incredibly delicious!! The possibilities are endless with the toppings!

    • hipfoodiemom

      October 19, 2012 at 5:26 pm

      Thank you!! Re: possibilities with the toppings- Yes, I know! Isn’t this great?! and I absolutely love puff pastry. . not only is it yummy but it’s pretty too! :)

  4. Linda | The Urban Mrs

    October 19, 2012 at 4:58 pm

    This is my fave! I love mushroom and add them in almost any kinds of meal. That looks soooo delicious and I’m glad it’s not rocket science to create one. Yay for simply delicioso!

    • hipfoodiemom

      October 19, 2012 at 5:30 pm

      Thank you! Yea for simply delicioso- love that! :P I’m glad you liked it, Linda! :) and yes- super simple!

  5. REMCooks.com

    October 19, 2012 at 9:27 pm

    Beautifully done. I bet that tart was indescribably delicious.

    • hipfoodiemom

      October 20, 2012 at 12:17 am

      It was. . :) Thank you so much, Richard!

  6. Audrey

    October 20, 2012 at 11:54 am

    There are lots of mushrooms there. Must be really yummy. Maybe I should try doing this one of these days and see how it turns out. Thanks for the recipe.

    • hipfoodiemom

      October 20, 2012 at 3:20 pm

      Yup, I love mushrooms so went a little crazy. . you should give it a try. The recipe is super simple! Thank you for the comment! :)

  7. Stacy

    October 20, 2012 at 8:40 pm

    I am in love with puff pastry! Isn’t it amazing? Your caramelized onions and mushrooms look amazing too! I can see an onion mushroom and thyme tart in my future!

    • hipfoodiemom

      October 22, 2012 at 5:29 am

      Hi Stacy, I do hope you give this recipe a try. . it’s amazing and so simple! :)

  8. Gray

    October 20, 2012 at 9:37 pm


    • hipfoodiemom

      October 22, 2012 at 5:29 am

      Thank you!

  9. Holly | Beyond Kimchee

    October 21, 2012 at 8:58 am

    What a neat savory pastry dish! Mushrooms are such a great ingredient to put on the pastry. With thyme, I bet it is so fragrant and delicious. Thanks for sharing.

    • hipfoodiemom

      October 22, 2012 at 5:30 am

      Thank you, Holly! Yes, this pastry was seriously wonderful, fragrant and delicious! :) I hope you give it a try!

  10. Mushrooms Canada

    October 22, 2012 at 1:22 pm

    WOW! This is absolutely gorgeous! A winning flavour combination, for sure. I also love the suggestion of the use of Crimini mushrooms…they are my favourite! Thanks for sharing another wonderful recipe.


    • hipfoodiemom

      October 22, 2012 at 9:03 pm

      Thank you so much, Shannon! I also LOVE cremini. These are my favorite mushrooms too! :)

  11. HyeJin

    November 19, 2012 at 4:56 am

    Hi Al! I’ve made this twice now. The first time I made the mistake of buying fillo and really didn’t like that texture at all. Second time, I made it with puff pastry and enjoyed it much more.

    Both times, I felt like the mushroom filling needed some acid, so I poured some balsamic vinegar in it while it was almost done caramelizing. The bv totally kicked it up a notch! I made it tonight for a friend that has become a new vegetarian… Going vegan soon, actually. He’s been doing it for over two months and he looked amazing! I swear he looked ten years younger since I last saw him three mos ago. His face was literally glowing.

    This was my menu:
    Onion, mushroom, thyme tart (with bv)
    Veg chili with boca veg burgers, black & kidney beans
    Acorn squash stuffed with celery, onions, walnuts, dried cranberries, & sage (very thanksgivingy)

    It was my very first vegetarian meal ever and it was yummy! We watched “Fat, sick, and nearly dead” after dinner and I made them a green juice after watching it. The entire night was a micro-nutrient love fest!

    My Green Juice:
    Baby greens (red & green Swiss chard, spinach, tat soi, & arugula)
    2 apples
    1 lemon
    Tiny knob of ginger
    Green grapes

    • HyeJin

      November 19, 2012 at 4:59 am

      P.S. love you girl and can’t wait to see you next month! Please let MJ & I know when you’ll be in town!

    • hipfoodiemom

      November 19, 2012 at 6:16 am

      Girl, LOVE it! I will totally try this!!! And we are definitely going to see you next month! :)

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  13. Kate McCracken

    November 13, 2014 at 10:21 am

    This looks so good I would like to make it for Thanksgiving but am unfamiliar with puff pastry. Pretty sure that this is a dumb question but by two sheets did you mean one on top of another or did you attach it longways? Hope I at least give you a laugh!
    Thank Kate

    • hipfoodiemom

      November 13, 2014 at 12:23 pm

      Hi Kate!! not a silly question at all!! I attached them both longways and folded up the edges all the way around the tart. If this will be the first time baking with puff pastry, you have picked a great recipe! I highly recommend all butter frozen puff pastry. . it is a lot more $$ but worth it. If you can’t find all butter puff pastry, the one by Pepperidge Farm works just fine, but this one is not all butter. Let me know how it works for you!!

  14. Kate+McCracken

    November 13, 2014 at 10:25 am

    This looks really great and I would like to make it for Thanksgiving but am unfamiliar with Puff Pastry. This is probably a dumb question but did you mean placing a second sheet on top of the first, or somehow attaching it lengthwise? Hope I at least gave you a laugh!

    Thanks Kate

    • hipfoodiemom

      November 13, 2014 at 12:29 pm

      Hi Kate, looks like I got your comment twice. Here’s my answer again:

      Hi Kate!! not a silly question at all!! I attached them both longways and folded up the edges all the way around the tart. If this will be the first time baking with puff pastry, you have picked a great recipe! I highly recommend all butter frozen puff pastry. . it is a lot more $$ but worth it. If you can’t find all butter puff pastry, the one by Pepperidge Farm works just fine, but this one is not all butter. Let me know how it works for you!!

  15. Robert M

    January 29, 2015 at 5:15 pm

    Looks great and will try it. The only commercially available all-butter puff pastry is not available here. Dufours was, but Whole Foods bought out the store that sold it and have Aussie brand. I cannot find out what the fat ingredients are…some sites say palm oil and other shortening. Is it really all butter as your recipe suggests? If so I’ll save myself work and buy it, otherwise it’s back to the pastry slab…


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