Oh, this Caramelized Onion Butternut Tart? It’s like wrapping yourself in a cozy blanket on a crisp autumn evening. Seriously, the moment those onions start slowly turning golden and sweet, your kitchen just fills with the most incredible aroma. What I love most is how the deep, earthy sweetness of the butternut squash just sings next to those tender, jammy onions, all nestled in a perfectly flaky crust. It’s honestly become my go-to for everything from a fancy dinner party starter to just a really comforting weeknight meal. This tart is pure magic, a little bit rustic, a little bit elegant, and always, always delicious.
Why You’ll Love This Caramelized Onion Butternut Tart
Honestly, this tart is a winner for so many reasons. First off, the flavor combination is just out of this world – that deep sweetness from the caramelized onions and the comforting earthiness of the butternut squash are a match made in heaven. And you know what else? It’s way easier to make than you think! It looks so impressive, but the steps are really straightforward. Plus, that flaky, buttery crust? Pure perfection. It’s the ultimate embrace for all those amazing fall veggies, making it super versatile. Whether you’re serving it as an appetizer, a light main with a fresh salad, or as part of a holiday feast, it always shines. And the smell? Trust me, your whole house will smell like pure comfort.
Ingredients for Your Caramelized Onion Butternut Tart
Alright, let’s talk about what you need for this absolute dream of a tart! It’s pretty straightforward, mostly pantry staples with a couple of stars of the show.
For the Crust
- 1.5 cups all-purpose flour
- 0.5 tsp salt
- 0.5 cup unsalted butter, cold, cut into cubes
- 4-6 tbsp ice water
For the Filling
- 2 large onions, thinly sliced
- 1 tbsp olive oil
- 1 tbsp butter
- 1 medium butternut squash, peeled, seeded, and cut into 1/2-inch cubes
- 2 large eggs
- 0.5 cup heavy cream
- 0.25 cup grated Parmesan cheese
- 1 tsp fresh thyme leaves
- 0.5 tsp salt
- 0.25 tsp black pepper
Essential Equipment for Making the Tart
So glad we’ve got our ingredients ready! Now, let’s talk tools. You don’t need a fancy kitchen for this tart, just a few trusty helpers. You’ll definitely want a good baking sheet for when we blind bake the crust. A nice big skillet is essential for coaxing all that sweetness out of the onions – no skimping on that slow caramelization! And of course, you’ll need a rolling pin to get that dough just right, and a 9-inch tart pan with a removable bottom to make it look all pretty when it’s done.
Step-by-Step Guide to Your Caramelized Onion Butternut Tart
Alright, let’s get this delicious Caramelized Onion Butternut Tart made! Don’t worry, it’s much more fun than it is complicated. We’ll break it all down, step-by-step, and I’ll share all my little tricks along the way.
Preparing the Tart Crust
So, the first thing we do is make our dough! Grab a nice big bowl – the bigger the better, so things don’t get too messy. Whisk your flour and salt together just to make sure they’re all friends. Now, for the butter. It HAS to be cold, like, straight-from-the-fridge cold, and cut into little cubes. This is the secret to a flaky crust, trust me! You can either use a pastry blender, which is awesome, or just get your fingers in there and rub the butter into the flour until it looks like coarse breadcrumbs. Don’t overwork it, okay? Then, we add the ice water, just a little bit at a time. You’re looking for the dough to just start coming together. It shouldn’t be sticky, just manageable. Once it forms a shaggy ball, gently press it into a disc, wrap it up tight in some plastic wrap, and let it chill in the fridge for at least 30 minutes. This lets the gluten relax, making it way easier to roll out later.
Caramelizing Onions for the Tart Filling
While our dough is having a little nap in the fridge, let’s get those onions going. This is where the magic really starts! Grab your biggest skillet, pop in the olive oil and the butter, and heat it up over medium-low heat. Now, add your thinly sliced onions. You need to cook these LOW and SLOW. Seriously, don’t rush this! Stir them every so often, and just let them do their thing. We’re talking about 25 to 30 minutes here, maybe even a little longer, until they are this gorgeous, deep golden brown, almost jammy sweetness. The house will smell AMAZING. Once they’re perfect, scoop them out and set them aside to cool a bit. It reminds me a bit of when I make my caramelized onion mashed potatoes – that slow, sweet transformation!
Assembling and Baking Your Caramelized Onion Butternut Tart
Okay, oven preheating time! Crank that baby up to 375°F (190°C). Time to roll out our dough. Dust your counter with a little flour, unwrap that chilled dough, and roll it into a circle that’s about 12 inches across. It doesn’t have to be perfectly round, rustic is beautiful! Carefully, and I mean carefully, drape your dough into that 9-inch tart pan. Gently press it into the bottom and up the sides. If there’s a bunch of extra dough hanging over, just trim it off with a knife. Now, for the blind baking… line that tart shell with parchment paper (don’t let it bunch up!), and fill it with pie weights or even some dried beans. Pop that in the hot oven for about 15 minutes. Then, take out the parchment and weights and bake for another 5 minutes, just until it’s looking a little golden. This step helps prevent a soggy bottom, which is a total tart crime!
While the crust is doing its thing, let’s whip up the filling really quick. In a medium bowl, just whisk together those eggs, the heavy cream, that lovely grated Parmesan cheese, fresh thyme leaves, salt, and pepper. Easy peasy!
Now for the grand assembly of your stunning Caramelized Onion Butternut Tart! Spread those beautifully caramelized onions all over the bottom of your pre-baked tart shell. Then, arrange your cubed butternut squash right on top of the onions. Finally, pour that gorgeous egg mixture over everything. Try to let it seep into all the little nooks and crannies around the squash. Pop it back into the oven and bake for about 25 to 30 minutes. You’ll know it’s ready when the filling is set – it shouldn’t jiggle too much – and the top is a lovely golden brown. Let it cool in the pan for about 10 minutes before you carefully remove that outer ring. Serve it warm and watch everyone’s eyes light up!
Tips for the Perfect Caramelized Onion Butternut Tart
Okay, so you’ve got the recipe, but here are a few little secrets from my kitchen to yours to make sure your Caramelized Onion Butternut Tart is absolutely, positively perfect. First off, don’t skimp on caramelizing those onions! Seriously, low and slow is the name of the game. If you rush it, they won’t get that deep, sweet flavor that just makes this tart sing. Also, make sure your butter and water are super cold for the crust – it really makes a difference in how flaky it turns out. When you’re cubing the butternut squash, try to keep the pieces pretty uniform in size. This just makes sure they cook evenly, so you don’t get some mushy bits and some crunchier ones. And when you pull your tart out of the oven, let it rest! A little patience here means it won’t fall apart when you slice into it. These little things really elevate your Caramelized Onion Butternut Tart from good to *unforgettable*.
Ingredient Substitutions and Notes
I get asked all the time if you can tweak this recipe, and the answer is always yes! That’s the beauty of cooking. If you’re not a fan of Parmesan, a nice sharp Gruyere or even a nutty cheddar would be lovely in the filling. The thyme is fantastic, but rosemary or even a pinch of sage would work wonderfully, especially if you’re leaning into those sage notes. And for the butternut squash, if you happen to have some leftover roasted sweet potatoes, they’d make a delicious stand-in. Just remember, sometimes substitutions can change the cooking time slightly, so keep an eye on it!
Serving and Storage for Your Tart
Alright, the moment of truth! This amazing Caramelized Onion Butternut Tart is best served warm, right out of the oven or after a little rest. It’s absolutely divine on its own, but I love pairing it with a fresh, crisp salad, like my fall harvest salad, to balance out all that rich goodness.
Got leftovers?lucky you! Let the tart cool completely, then wrap it snugly in plastic wrap or pop it into an airtight container. It’ll keep beautifully in the fridge for about 3 days. To reheat, just pop a slice in a 350°F (175°C) oven for about 10-15 minutes until it’s warmed through. You won’t even know it’s not fresh-baked!
Frequently Asked Questions about Caramelized Onion Butternut Tart
Got questions about this delicious tart? I’ve got answers!
Can I make the tart crust ahead of time?
Absolutely! The crust dough can be made up to 2 days in advance and kept chilled in the refrigerator. Just let it sit on the counter for about 15-20 minutes to soften slightly before rolling it out. It makes assembly so much quicker on baking day!
What other vegetables can I add to the filling?
Feel free to get creative! Some lovely additions include a handful of sautéed spinach, some roasted mushrooms, or even some finely chopped kale tossed in with the squash. Just make sure any extra veggies are cooked down a bit beforehand so they don’t add too much moisture to the tart.
Can I use store-bought pie crust?
You totally can if you’re in a pinch! While my homemade crust is pretty special with its flaky texture, a good quality store-bought pie crust will work just fine. Just make sure it fits your 9-inch tart pan nicely.
How do I know when the tart is fully baked?
You’ll know your Caramelized Onion Butternut Tart is ready when the filling is set – it shouldn’t have a big wobble in the center – and the top has a beautiful golden-brown color. The edges of the crust should also look nicely baked. If you gently insert a knife near the center, it should come out mostly clean.
Nutritional Information
Just a heads-up, the nutritional info below is an estimate! It can totally change depending on the exact brands you use and how you prepare everything. But as a general idea, a serving of this delicious Caramelized Onion Butternut Tart usually comes in around 400-450 calories, with about 25-30g of fat, roughly 10-15g of protein, and around 30-35g of carbohydrates. Enjoy!
Caramelized Onion Butternut Tart
Ingredients
Equipment
Method
- Make the crust: In a large bowl, whisk together flour and salt. Cut in the cold butter using a pastry blender or your fingertips until the mixture resembles coarse crumbs. Gradually add ice water, 1 tablespoon at a time, mixing until the dough just comes together.
- Form the dough into a disk, wrap in plastic wrap, and refrigerate for at least 30 minutes.
- Caramelize the onions: While the dough chills, heat olive oil and butter in a large skillet over medium-low heat. Add the sliced onions and cook slowly, stirring occasionally, for 25-30 minutes, or until deeply golden brown and sweet. Set aside.
- Preheat oven to 375°F (190°C). On a lightly floured surface, roll out the dough into a 12-inch circle. Carefully transfer the dough to a 9-inch tart pan with a removable bottom, pressing it into the bottom and up the sides. Trim any excess dough.
- Blind bake the crust: Line the tart shell with parchment paper and fill with pie weights or dried beans. Bake for 15 minutes. Remove the parchment and weights, and bake for another 5 minutes, or until lightly golden.
- Prepare the filling: In a medium bowl, whisk together eggs, heavy cream, Parmesan cheese, thyme, salt, and pepper.
- Assemble the tart: Spread the caramelized onions evenly over the bottom of the pre-baked tart shell. Arrange the cubed butternut squash over the onions.
- Pour the egg mixture over the squash and onions, ensuring it fills the gaps.
- Bake: Bake for 25-30 minutes, or until the filling is set and the top is golden brown. Let the tart cool in the pan for 10 minutes before removing the outer ring.
- Serve warm.