Caramelized Onion Tart with Gruyere

This is a recipe for Caramelized Onion Tart with Gruyere Cheese. This combination of sweet and savory filling is heavenly. Balsamic vinegar, bacon and thyme make this an awesome savory tart to serve as an appetizer, or a light dinner with a simple tossed salad.

It’s late July in Colorado and that means I’m more excited to cook than any other time of year. Our Colorado fresh produce is starting to come in, fresh sweet corn, Rocky Ford Melons and Musso Farms is heralding the news that it’s Pueblo Chile Season. Those chile roasting drums are firing up.

I still have most of a bucket of Vidalia Onions in dark storage (back corner of my pantry) that I need to use before they go bad. And after all there are new Colorado onions to take their place now. I can’t think of a better way to use them than in this onion tart.

This caramelized onion tart recipe comes from the Pastry Kitchen at Cook Street Culinary School. We didn’t actually make this particular tart while I attended, but I found it in the index of recipes that were provided to us by the school.

I love everything about this tart. The Vidalia onions become even more sweet with a long stove top sautee. And even more delicious cooking them with bacon and even more interesting with the addition of balsamic vinegar. Who can resist that combo of ingredients? Not us.

The seasoning for this onion is simple with fresh thyme. I used Lemon Thyme from my garden, but of course any fresh thyme will add a delicious note.

How to Blind Bake A Tart Shell:

I hope you’ll consider taking the time to make a homemade pie shell for this tart recipe. One of the great take-aways from Culinary School was how to make an All Butter Pie Crust. It’s really very easy and a skill I feel every home cook should learn. As French technique you’ll also see it referred to as pate brisee.

When making pies or tarts that call for a delicate filling a filling that’s already been cooked, you’ll need to blind bake the shell first, which simply means one pre-cooks the dough before adding the filling. That’s because the hour or so cooking time that it takes to bake the crust would over-cook some fillings, such as this onion tart filling.

Simply place the dough into the pie or tart pan and gently form the dough to the shape of the pan. Then cover the dough with a round of parchment paper that’s been cut to size and place pie weights or dried beans in the parchment paper to hold the paper against the dough. Chill the crust for thirty minutes. I’ve even placed it in the freezer to make sure it gets nice and cold.

Bake the pie dough in an oven preheated to 375 degrees for twenty minutes.

Remove the pie from the oven, and lift out the paper and weights. Prick the bottom of the crust all over with a fork, to prevent bubbles. This is called docking. Return the crust to the oven and bake for an additional 15 to 20 minutes, until the crust is golden all over.

Now we’re ready to make this onion tart.

Recipe for Caramelized Onion Tart with Gruyere, Bacon and Thyme:

I’ve used a 9-inch tart pan for my recipe. You can also use an 8-inch pan for a thicker tart. Or even 8 individual 4″ to 5″ small tart pans.

I hope you give this Caramelized Onion Tart recipe a try. And if you do, please come back and let me know how you liked it and give the recipe a star rating.

Your feedback is valuable to me for developing future recipes. And if you have a favorite onion tart recipe, let me know, I’d love to give it a try.

Once I made my first tart, I became quite obsessed with making more and more. If you’re looking for more tart recipes, you won’t want to miss:

• Creme Fraiche Cranberry Pear Tart
• Fresh Tomato Tart Recipe
• Peach Curd Tart with Basil Sugar Whipped Cream
• French Pear Tart Bourdaloue with Apricot Rum Glaze
• And this Chocolate Covered Strawberry Ice Cream Tart, from Melanie Makes

4 from 3 votes

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Caramelized Onion Tart with Gruyere

Prep Time

15 mins

Cook Time

20 mins

Total Time

35 mins

 

Caramelized Onion Tart with Bacon and Gruyere Cheese and. Simply seasoned with fresh thyme and balsamic vinegar, This creamy cheese tart is a winner.

Course: Appetizer

Cuisine: French

Keyword: Carmelized Onion Tart

Servings: 8

Author: Lea Ann Brown

Ingredients

• 1 Pie Crust preferably homemade - blind baked
• 3 large onions emincee'd (thin sliced)
• 3 ounces bacon fine diced
• 1 tablespoon sugar
• 1/2 teaspoon salt
• 2 teaspoons balsamic vinegar
• 2 tablespoons fresh thyme chopped
• fresh ground black pepper
• 1/4 cup heavy cream
• 1 cup gruyere grated

Instructions

1. Cook the bacon, stirring often, in a large non-stick fry pan over medium heat until almost crisp. Add the onions, sugar and salt and cook, stirring often until they cook down by two thirds. 

2. Add the 2 teaspoons vinegar, reduce heat to medium-low, and continue to cook until the onions are an even golden brown and softened, 15 - 20 minutes. (depending on the onions)

3. Stir often and scrape up any brown bits clinging to the bottom of the pan. Remove from heat, stir in the thyme and allow the ingredients to cool slightly. Taste, season with black pepper and add more salt if necessary.

4. Preheat oven to 350 degrees. Stir the cream into the caramelized onions until thoroughly combined. 

5. Place the filling in a 9" tart shell that's been blind baked and spread it evenly with the back of a spoon. Sprinkle grated gruyere on top. Bake in oven until the filling is set, about 15 minutes. 

6. Serve warm or at room temperature. Garnish with a sprig of thyme.

Recipe Notes

You can use a 9" tart pan, an 8" tart pan for a thicker tart. Or even 4 - 5 inch individual tart pans.

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I’m sharing this onion tart recipe with Meal Plan Monday at Southern Bite.