Caramelized Onions, Mushrooms and Gruyere Tartlets

by Shumaila

I love Michelle’s site- The Brown Eyed Baker.

In the past I have made the portobello pesto pizza adapted from her site, and it was wonderful.

Coincidentally (although it was not intended) I chose another mushroom recipe from her site to try.

Last week, it was my turn to host the weekly coffee meets we ladies of our small town have every Friday.These get-togethers are my lifeline and thanks to the amazing group of people I have met through these weekly affairs, living in this town has actually become enjoyable.

While browsing through FoodGawker for some appetizer ideas to make for my friends, I came across these caramelized onions and mushroom tartlets. One look at the recipe and its rave reviews, I was sure this is what I had to make.

I love mushrooms.

And caramelized onions. And Gruyere.

And I loooooooove puff pastry. So I knew these would be delish.

And how right I was!

These were a hit at coffee. One of my friends, who doesn’t even like mushrooms, loved them.

So did V. (And you all know about V’s “love” for mushrooms).

Probably the mushroomy taste gets hidden in the thyme (which I think just adds so much flavor to these tartlets), the broth and caramelized onions. Plus, anything on puff pastry has to taste great (what with all the butter!), besides looking fancy.

As Michelle puts it:

These are equal parts sophisticated and easy – the best type of entertaining food in my book.

If you plan to make smaller tartlets, like I did, I would suggest to chop the mushrooms a little smaller. Although I did not do so, I felt the mushroom chunks to be quite large for the size of the tartlets. (The picture you see below is of the bigger sized tartlets I made for V and me with the leftover filling)

Before I leave you with the recipe, I have two exciting things to share with you. featured my Five Minute Nutella Mug Cake recipe on their site.


My Roasted Stuffed potatoes are featured in today’s delcious links at The Kitchn of the Apartment Therapy fame 🙂

There is one thing submitting your photos/recipes and getting published but there is an entirely different joy when you get published without asking for it. I should be humble about it, but well, I have to admit it, I felt great when I got to know! So I just had to share! 🙂


Adapted from The Brown Eyed Baker

This is a great finger food. The filling does take some time to make- about an hour, although most of it is not active cooking time. You can make these ahead, by making the filling a day before. You can also cut the puff pastry into the desired shapes and freeze them on the baking tray, covered  with plastic wrap.Assemble and bake them just before your guests arrive. These are perfect game day treats (think Super Bowl) and even mushroom haters would love them. Just don’t mention they have mushrooms and they would never know.

Michelle uses wine for the cooking the filling, but I used chicken broth, since my friends were bringing their kids along and even though the wine gets cooked out, I did not want to take the risk.

Makes about 16 3 inch tartlets ( Since I made 20 2-inch tartlets, I had plenty filling left and used it to make some mini tarts for V and me the next day).


  • 1 tablespoon olive oil
  • 1 large yellow onion, thinly sliced
  • 1 tablespoon unsalted butter
  • 16 ounces white button mushrooms, thinly sliced
  • 1 clove garlic, chopped
  • ½ teaspoon dried thyme
  • Salt and pepper, to taste
  • ¼ cup white wine (I substituted with chicken broth, you can use vegetable broth as well)
  • 2 sheets puff pastry (thawed according to directions on package, or make your own- directions here)
  • 1 cup shredded Gruyere cheese (can substitute any variety of Swiss cheese)
  • 1 egg + 1 tablespoon water, beaten together (for the egg wash)
  • Handful of parsley, chopped


  1. Heat the olive oil in a wide, heavy-bottomed pan over medium-low heat. Add the onions. Cook, stirring occasionally, until they begin to caramelize, about 20 minutes. See quick tip below.
  2. Add the butter to the pan. Once melted, add the mushrooms and saute, stirring occasionally, until they are completely soft and all of the liquid evaporates. Takes about 20 minutes.
  3. Add in the garlic and thyme. Saute for about a minute. Season with salt and pepper, to taste.
  4. Add the chicken broth (or wine), scraping the bottom of the pan to pull up all of the browned bits, and cook until all of the liquid has evaporated. It took about ten minutes. Remove from heat. Let cool.
  5. Preheat oven to 400 degrees F and line two baking sheets with parchment paper.
  6. Unfold the thawed sheets of puff pastry and cut out circles from the dough, placing them evenly spaced on the baking sheets. I used a bottle cap that was 2 inches in diameter as the cutter, as I don’t own any cookie cutters. Using a very sharp knife, make four small scores around the perimeter of the dough, about ¼ to ½-inch from the edge as shown below.
  7. Top the rounds of puff pastry with a small spoonful of the onion and mushroom mixture, trying to keep the filling within the score marks. Top with the shredded Gruyere cheese. Brush the edges of the dough rounds with the egg wash.
  8. Bake until the pastry is golden brown, about 15 to 25 minutes. Garnish with fresh chopped parsley.

Quick Tips: To reduce your time in the kitchen, chop the onions first and start caramelizing them. While they are left to caramelize, prep the other stuff.

For another version of caramelized onion tarlets (that don’t use puff pastry) check this recipe.