Caramelized Onion & Blue Cheese Tarts

These Caramelized Onion Tarts can be made to serve two or turned into a tasty party appetizer!  

Yup, more caramelized onions - I just love them so much I want to keep sharing all the amazing and tasty things you can make with them! While they are such perfect winter food, you can really use them all year long! And they even freeze well so go ahead and make a bigger batch while you are cooking up this recipe so you have them on hand for later!  

I actually first made these tarts, in the miniature version, for New Year's Eve with the caramelized onions that were leftover from my Caramelized Onion Dip and they were such a big hit that I decided to write up a post about them.

Recipe Ingredients

• Onions: Yellow onions are the ideal choice for this recipe. You'll need one large onion to make the tarts but I highly recommend caramelizing two at the same time so you have leftovers!
• Blue cheese: Any type of blue or gorgonzola will work.
• Pancetta: I prefer to use a thinly sliced pancetta in this reicpe. I'll chop it into strips before I cook it.
• Pie crust: Pre-made pie crust works well for this recipe.
• Sherry: I keep a bottle of decent quality sherry in my kitchen. You don't necessarily need something really expensive but since it keeps forever and you generally only use small amounts, it's worth buying higher quality than grocery store cooking sherry.
• Pantry staples: Olive oil, unsalted butter

How to make this recipe

You can make these tarts two different ways - don't you love recipes that have options?!   The first option is individual serving tarts, made in small quiche or tart dishes. The recipe will make 4 tarts that size.

Or if you want to transform this into a party appetizer you can make them in mini muffin pans, which will give you 24 little bite-sized tarts. Given all the flavor of the ingredients, I used Pillsbury pre-made pie crusts, which means if you already have the onions made you can have these lovely tarts ready in less than 20 minutes.

Caramelize the onions. The first step in this recipe is to caramelize the onions. You can do this ahead of time if you want to cut down your prep time. If doing it all at once then leave about an hour for this step.

Prepare the crust. You'll want to slightly roll the crust and then cut it to the appropriate size depending in the type of pan you are using.

Prepare the tarts. Once the crust is in the pan, you'll add the caramelized onions, pancetta and blue cheese to each tart. Then bake and they are ready to enjoy.

Tools you'll want for this recipe

Small tart pans – These are ideal for individual tarts and quiches. I got mine at Crate and Barrel years ago, but these are very similar. You can probably find them on Amazon as well.

Mini Muffin pan – These are useful for many things but if you want to make the mini appetizer version then you'll need either two 12-cup pans or one 24-cup pan.  

More appetizer recipes

• Cheesy Swiss & Mushroom Pull-Apart Bread
• Cranberry Brie Tarts in Phyllo Cups
• Instant Pot Queso Dip without Velveeta
• Roasted Tomato Ricotta Crostini
• Healthy Cowboy Caviar

Caramelized Onion & Blue Cheese Tarts Recipe

Author: Kathryn | Urban Foodie Kitchen

These Caramelized Onion Tarts can be made to serve two or turned into tasty, mini party appetizers!  

5 from 2 votes

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Prep Time 10 minutes mins

Cook Time 1 hour hr 20 minutes mins

Total Time 1 hour hr 30 minutes mins

Course Appetizers

Servings 4 or 24 tarts

Ingredients

  

1x2x3x

• 1 large onion, vertically sliced
• 1 tablespoon unsalted butter
• 1 tablespoon cooking sherry, divided
• 1 ½ ounces thinly sliced pancetta, chopped
• ½ tablespoon avocado or olive oil
• 1 box premade pie crust
• ½ cup crumbled blue cheese

Instructions

 

• Heat the oven. Preheat the oven to 350°F. 
• Caramelize the onions. Melt the butter in a medium pan over medium-low heat.  Add the onions, stir and let them sit for about 20 minutes so they can begin to caramelize.  Stir every 10 minutes or so, ensuring they don't turn too dark.  Once the fond, which is the dark bits that form on the bottom of the pan, starts to form, deglaze the pan by adding the sherry and scraping the pan with a silicone spatula.  Scrape as much of the fond back into the onions as you can.  
• Cook the pancetta. While the onions are caramelizing, add the pancetta to a small skillet over medium heat.  Cook for 5-6 minutes or until the pancetta is browned and crisp.  Remove from the pan and drain on a plate lined with paper towels.  
• Prepare the crust. Lightly coat 4 mini quiche (or tart) pans or 24 mini muffin cups with oil. Unroll one of the pie crusts on a rolling mat or clean counter.  Roll out slightly with a rolling pin. If using quiche pans, cut the crust in half and press into half into each quiche pan. Cut the edges s so they are even with the rim of the pan.  Repeat with second pie crust.  You will have leftover pie crust.  
• If using mini muffin pans, cut 24 2 2/1 inch circles (a biscuit cutter or small glass works well for this).  You will need to scrape the pieces and re-roll one time.  Again, you will have some leftover crust.  Press the circles into the muffin cups.  
• When the onions are done cooking, divide them evenly between whichever type of pans you are using. Then sprinkle each tart with a little pancetta and some blue cheese.  Bake for 16 - 20 minutes or until crust starts to turn golden brown.  
• Remove from oven and let cool slightly.  If making mini tarts, remove them from the pan after a few minutes.  Serve warm.  

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This post was originally published in February 2016. It was updated in November 2021 with some new information. No changes were made to the original recipe.