Caramelized Onion, Mushroom & Gruyere Tartlets
Continuing down the road of appetizers, dips and snack food leading up to the Super Bowl, I give you this somewhat “upscale” game day food. Caramelized onions, mushrooms and Gruyere cheese are baked atop circles of puff pastry for a flaky, savory and delicious appetizer. Another occasion that this appetizer would be great for? A baby shower! Fellow food blogger Annie from Annie’s Eats is expecting her second baby in April (a girl!) and a group of bloggers organized a virtual baby shower to celebrate Annie’s bundle of joy, and of course we all brought food to the party! Since appetizers are my second love behind desserts and this is Super Bowl week, I definitely wanted to go that route, and thought that these little tartlets would be something Annie and other ladies at a shower would certainly enjoy. To see all of the great drinks, appetizers, main dishes and desserts that other bloggers contributed to the virtual shower, head on over to Annie’s and Courtney’s blogs for the roundup. For more on the tartlets, keep reading!
One of the great things about these tartlets is that you can cut the circles smaller or larger depending on how many you want to serve or how truly bite-size you want them to be. I did 3-inch circles, but you can definitely adjust depending on your needs.
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These are equal parts sophisticated and easy – the best type of entertaining food in my book. You could even prepare the caramelized onions and mushrooms ahead of time and then assemble and bake right before guests arrive. Perfect for a football game or a baby shower! :)
One year ago: English Muffins
Caramelized Onion, Mushroom & Gruyere Tartlets
Ingredients
- 1 tablespoon olive oil
- 1 large yellow onion, thinly sliced
- 1 tablespoon unsalted butter
- 16 ounces (453.59 g) white button mushrooms, thinly sliced
- 1 clove garlic, chopped
- ½ teaspoon (0.5 teaspoon) dried thyme
- Salt and pepper, to taste
- ¼ cup (60 ml) white wine, can substitute chicken or vegetable broth
- 2 sheets puff pastry, thawed according to directions on package
- 1 cup (132 g) 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
Instructions
- Preheat oven to 400 degrees F 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 saute, stirring occasionally, until they are completely soft and all of the liquid evaporates, about 20 minutes.
- Add the garlic and the thyme and saute 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.
- Unfold the thawed sheets of puff pastry and cut out circles from the dough, placing them evenly spaced on the baking sheets. Using a very sharp knife, make four small scores around the perimeter of the dough, about ¼ to ½-inch from the edge.
- 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.
- Bake until the pastry is golden brown, about 15 to 25 minutes. Garnish with fresh chopped parsley.
Did you make this recipe?
Leave a review below, then snap a picture and tag @thebrowneyedbaker on Instagram so I can see it!
This is by far the best recipe for this tart with its attention to detail. Always proven to be a hit with party guests and friends over the years.
These were delicious and snapped up by my dinner party guests. I will say that i was nervous how they would turn out, b/c when i cooked the mushrooms after the onions, I had chopped them up pretty finely using the shredder attachment on my food processor (I doubled this recipe so there were a LOT of mushrooms i didn’t want to chop), and there was just a lot of liquid. I covered the pan (I prob used the wrong kind of pan – a nonstick big deep frying pan, maybe i should’ve used my All Clad or Dutch oven), and the amount of liquid just kept rising; i tried boiling, low heat, etc. Ultimately I had to pour a lot of it out (which was a waste b/c when i tasted it it was delicious and basically was mushroom soup). I recommend adding more instruction about how to get the liquid to soak up – be it the type of pan, or NOT covering during cooking mushrooms. But even when I stored the mixture the previous day before cooking, even more liquid forms. When i did put on the pastry I just pulled from the top without the liquid. Still could not get them to look as pretty as yours, even tho i cut with a cookie cutter and used a shot glass for the inner ring (it was a perfect 1.5″ round!). I think they looked definitely homemade and like i said, people enjoyed them. I didn’t even use up half the cheese, it just didn’t stay on top of hte mixture well enough so i don’t know how you could’ve used that all! THanks, prob won’t make again b/c it was a lot of work ,but sure delicious.
Delicious and always gets rave reviews from dinner guests. To get them to rise properly make a square in the center so you basically have a circle with a scored square in the center. I found that brushing the dough with egg wash prior to placing the mushroom mixture on the dough is easier and keeps the dough from getting soggy.
Absolutely love this recipe! I’ve modified it with different cheeses and even some prosciutto, and it always turns out wonderful! (except for a time I forgot to score the pastry)
I made this on a sheet pan as one large tart and it was delish!
Can I make these tartlets using the frozen mini tart shells – precook the filling add to defrosted shells and then bake as to the packet instructions
No review just yet…but….want to make these. Don’t suppose I can freeze them, right? Maybe just prep the topping ahead? Can I prep the puffpastry and keep the rounds in the fridge for an hour or so before guests arrive
Can you bake this in one big round or rectangular tart and then just slice after cooking?
Yes, that would definitely work!
Hi, can I put the puff pastry in a muffin tin and fill it with the onion and mushroom?
They were the bomb
Can these be frozen?
Yes, definitely!
The caramelized onion, mushroom and gruyere cheese tartlet recipe sounds great, but is something missing in the Directions? I don’t fully understand the part about cutting the 4 score marks. Do you cut them around the perimeter and THEN fold up the edges? Or, do you cut them at a point 1/4 to 1/2 inch in from the perimeter just so the pastry can “breathe” as it cooks, and not fold up the sides??
Look forward to hearing back about this.
Hi Dale, You score around the perimeter, but do not fold up the sides. Enjoy!
If we are vegetarian and we don’t eat egg we can replace by what to brush the dough thxs
Hi! This recipe looks delicious (and seems that way from the many comments). I was wondering if I could make this recipe but use pie dough instead of puff pastry? Thank you in advance!
Yes, pie dough would definitely work, too!