Caramelized Onion, Mushroom and Gruyère Tartlets

Who doesn’t enjoy a savory tartlet?  They’re tiny, delicate, delicious and the perfect party food.  Cook the onion and mushroom mixture ahead of time so you are not rushing to pop these in the oven.  I like that this recipe doesn’t call for any tart pans leaving less to clean up – yay!  Be creative and experiment by using different size circles.  Perhaps use a bread and butter plate as an outline to cut the pastry and serve this with a light salad.  These tartlets are very good the next day as the flavors will have intensified. All you need to do is warm them up.   I am enjoying one now as I write this!

Makes 16 3-inch tartlets
adapted from Brown Eyed Baker

1 tablespoon olive oil
1 large yellow onion, thinly sliced
1 tablespoon unsalted butter
16 oz. white button mushrooms, thinly sliced
1 clove garlic, chopped
fresh thyme, to taste (can also use dried)
salt and pepper, to taste
¼ cup white wine (can substitute chicken or vegetable broth)
2 sheets puff pastry (thawed according to directions on package)
1 cup shredded Gruyère cheese (or any variety of Swiss cheese)
1 egg plus 1 tablespoon water, beaten together (for the egg wash)
garnish with fresh thyme (optional)

Preheat oven to 200c (400f) and line two baking sheets with parchment paper. Heat the olive oil in a wide, heavy-bottomed pan over medium-low heat and add the onions. Cook, stirring occasionally, until they begin to caramelize, about 20 minutes. Add the butter to the pan. Once melted, add the mushrooms and sauté, stirring occasionally, until they are completely soft and all of the liquid evaporates, about 20 minutes. Add the garlic and thyme and sauté until fragrant, about 1 minute. Season with salt and pepper to taste. Add the wine, scraping the bottom of the pan to pull up all of the browned bits, and cook until all of the liquid has evaporated. Remove from heat.

Carefully unfold the thawed sheets of puff pastry and cut out circles from the dough (cookie cutter works well or a glass), placing them evenly spaced on the baking sheets. Using the tip of a sharp knife, lightly run the knife along the edge (about 1/4 to 1/2-inch) of the perimeter of the dough but don’t cut all the way through. Place a small spoonful of the onion and mushroom mixture, keep the filling within the score marks. Top with the shredded Gruyère cheese. Brush the edges of the dough rounds with the egg wash.

Bake until the pastry is golden brown, 20 to 25 minutes. Garnish with fresh thyme.

The Culinary Chase’s Note:
The aromas of onions, mushrooms and garlic permeated the kitchen giving my senses a preview of what was yet to come. These little discs did not disappoint and it took a lot of will-power to stop after eating my third one.  Enjoy!


  1. Judy@explore on April 5, 2012 at 23:23

    I’m salivating as I read this and look at the wonderful pictures! Can’t wait to make them! But…there is one step that I think you’ve left out, haven’t you? After you score 1/4-1/2″ within the perimeter of the dough and add the filling – you must have to bring the dough up to form sides, then you brush the edges with egg – right? You’ll have a better description of it than I.

  2. The Culinary Chase on April 5, 2012 at 23:44

    Thanks Judy! Your question regarding the dough…answer: no, you don’t have to form the sides because when it goes into the oven, the scored area acts as a barrier that puffs up. 🙂

  3. Judy@explore on April 6, 2012 at 00:29

    Oh neat – that’s even easier than I thought! Thanks, Heather 🙂

  4. Emily (New York, NY) on April 9, 2012 at 15:34

    I must have been totally missing out my whole life thus far, food wise of course – every time I see new recipes on your site (that I loove!), I see ones I’ve never even thought about making or eating! They always sound (and look!) so delicious, I cannot wait to have a chance to make some, especially this one. I didn’t even know how much I love anything with caramelized onions until about two months ago – haha. Thanks for sharing these wonderful recipes! Hope to stay in touch via our blogs!

  5. The Culinary Chase on April 9, 2012 at 17:18

    Thanks Emily for your very sweet words! Unless someone leaves me a comment like you have, I never really know if the food I post inspire people to cook so thank you for sharing your note with me. Maybe you can do a guest posting on my site. 🙂 Cheers!

  6. Emily (new york, NY) on April 10, 2012 at 18:39

    That would be awesome, I would love to talk more about the potential of a guest post. I’m sure you are busy busy but if you would like to discuss this more, I would love to hear what you would look for! Feel free to email me at adasinteriordesign@gmail .com! Have a beautiful week!