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Gruyère & Caramelized Onion Tart

Better Than I Imagined

Gruyère cheese has become one of my favorite cheeses since my time living in Sweden after high school. Yes, Gruyère is a type of Swiss, not a Swedish cheese but it was in Sweden where I ate it for the first time and it turned me into a cheese-crazed person.Gruyère Onion Tart

I have been thinking about making this tart for decades but the puff pastry scared the crap out of me. I thought that there is no way I would be successful in making it. Then I learned that most folks I know that use puff pastry, buy it. So I gave in on that front and made this Gruyère & Caramelized Onion Tart for a gathering at a friends house. It was a huge hit. So I wanted to share it with you.

Gruyère & Caramelized Onion Tart


3 medium yellow onions, sliced thin
2 tbsp olive oil
2 tbsp butter

1 tsp garlic powder
salt & fresh ground pepper, to your liking
½ tsp dried thyme
1/4 cup palm sugar (may substitute with brown sugar)
Balsamic glaze*, a generous swirl
2 cups grated Gruyére cheese, adjust more or less to your liking

1 Tbsp milk
1 1/3 frozen puff pastry sheets, slowly thawed per box instructions
fresh thyme leaves


Slice your onions as thin and uniform as you can. If using a mandolin about 2-3 cm is perfect. I do not have a mandolin so I use my English muffin splitter.Gruyère Onion Tart

In a dutch oven low-medium heat, melt the 2 tbsp butter and 2 tbsp olive oil, then add the sliced onions.

Cook the onions until they are translucent, stirring often.  After the onions are translucent add the garlic, thyme, salt & pepper, and palm sugar.Gruyère & Caramelized Onion Tart

Stir in these ingredients and cook for about 10-15 minutes with limited stirring. Add the balsamic glaze.Gruyère & Caramelized Onion Tart

Blend in with onions. Cook for 10 minutes.

Cover with a lid to allow steam to build up (about 5 minutes). Remove the lid and carefully scrape the toasty brown bits from the bottom of the pan. Cook until the liquid has cooked off and the onions begin to stick and crust up un the bottom of the pan again. Cover with a lid again to allow steam to build up (about 5 minutes). Remove the lid and carefully scrape the toasty brown bits from the bottom of the pan. Continue this until the onions have gone from golden to brown. Set aside to cool.

 Preheat your oven to 400 degrees.

Lay the 10×10 puff pastry out onto a cookie sheet. Lay the additional piece next to it and use a wet finger to blend the sheets together to make a rectangle.

About 1 inch inside the pastry dough, score the edges all the way around (basically making a smaller rectangle inside the dough). Use a knife to do this, but be careful not to cut all the way through the dough. Scoring the dough will allow an edge ‘crust’ to puff up.

Scoop the onion mixture into the smaller rectangle in the middle of the puff pastry sheet evenly spreading to the scored cut line. Sprinkle on the Gruyére cheese over the onions. Using a pastry brush, brush the edges of the pastry with the milk.

Bake for 23-24 minutes, or until the puff pastry puffs up, and the pastry and cheese is golden brown.

Cut into individual pieces, then sprinkle with fresh thyme leaves for aroma, flavor and a touch of color.

Serve warm or room temperature.

Gruyère & Caramelized Onion Tart


* now found in most grocery stores and on Amazon

Download PDF of Recipe Here: Gruyère & Caramelized Onion Tart

That is all for now.




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