Caramelized Onion Tart with Gruyere

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

Cuisine French

Prep Time 15

Cook Time 1 15

To Make The Pie Crust 1

Total Time 2 30

Servings

Calories 266kcal

Prepare Blind Baked Pie Crust. You'll find complete instructions in my Pie Crust Article.
Cut the bacon into 1/2 lardons and cook in a large fry pan, stirring often until soft crispy. Remove bacon to a plate and discard all but about 2 tablespoons of the grease.
In the meantime, cut the ends of each onion, remove skin and slice into 1/4 inch rounds. Reduce heat medium low. Add the onions, sugar and salt and cook, stirring often until they cook down by two thirds, about 30 minutes. Add a generous 1 tablespoon pat of butter if you feel the bacon didn't yield enough grease. (I always do anyway)
Add the balsamic vinegar, reduce heat to low, and continue to cook until the onions are an even golden brown and softened, 15 minutes.
Stir often and scrape up any brown bits clinging to the bottom of the pan. while the onions cook, watch them closely, you don't want them to burn, just to become golden and caramelized.
Remove from heat, stir in the thyme, black pepper and cooked bacon. Allow the ingredients to cool slightly. Stir the cream into the caramelized onions until thoroughly combined.
Preheat oven to 350 degrees.
Place the filling in the 8" blind baked tart shell 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.
Serve warm or at room temperature. Garnish with a sprig of thyme.

Tips For Success

- Don't rush the onions. It will take at least 45 minutes for them to be golden and caramelized. And don't cook them on a higher heat. The lowest setting on the burner will create the best results. And slice them evenly for even cooking.

- You MUST use a pie shell that has been cooked, this is called a Blind Baked Pie Shell. When making pies or tarts that call for a filling that's already been cooked, you'll need to blind bake the shell first. Which simply means to pre-cook the dough before adding the filling. That's because the hour or so cooking time that it takes to bake a pie crust would over-cook the fillings, such as in this Caramelized Onion Tart Filling. It's already cooked, and simply needs to "set up" with a short baking time.

- Use A Homemade Pie Crust: 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.

- Please reference my article on making a homemade pie crust for the recipe and instructions on blind baking.
- Place tart on a baking sheet to bake. Tart pans have a removable bottom. Using a sheet pan makes it easier to get it in and take it out of the oven, without disturbing the removable disk