Golden cubes of roasted butternut squash, tangy goat cheese, and deeply caramelized onions all nestled into a flaky tart shell—this Butternut Squash Caramelized Onion Tart is cozy, elegant, and just bursting with fall flavor. It’s the kind of savory tart that steals the spotlight at brunch, becomes the star of a holiday appetizer spread, or even serves as a stunning vegetarian main dish for dinner.

The sweetness of the squash pairs perfectly with the rich depth of caramelized onions, while creamy cheese adds that crave-worthy contrast. Add a sprinkle of fresh herbs, and you’ve got something that’s both rustic and refined. Whether you’re entertaining or treating yourself to something special, this tart brings seasonal comfort with every bite.

Preparation Phase & Tools to Use

To make this tart come together beautifully, a few key tools make all the difference:

Tart pan with removable bottom: Essential for achieving a crisp crust and easy release for that picture-perfect presentation.
Mandoline or sharp knife: To slice onions thinly and evenly—this helps them caramelize evenly and quickly.
Baking sheet: For roasting the butternut squash pieces to sweet, golden perfection.

Mixing bowls: You’ll need one for the filling mix and another to toss the squash in oil and seasoning.
Skillet: To bring out the rich, sweet flavor of the onions through low and slow cooking.
Oven: Everything gets baked to meld flavors and finish the crust to golden brown.

These tools don’t just help with efficiency—they’re the secret to a balanced texture and flavor. A properly roasted squash, golden crust, and jammy onions all rely on these techniques and the right equipment.

Ingredients for the Butternut Squash Caramelized Onion Tart

Every ingredient in this tart is chosen for flavor, texture, and balance. Here’s what makes each component essential:

Butternut squash: The heart of the tart. When roasted, it becomes tender and slightly sweet, creating a cozy, rich base.

Yellow onions: Slowly caramelized, they add deep, savory sweetness and complexity.
Goat cheese or feta: Offers creamy tang that balances the sweetness of squash and onions.
Eggs: Help bind the tart filling while adding richness.

Heavy cream: Creates a luscious custard texture within the tart.
Olive oil: Used for roasting and sautéing, enhancing flavors and helping with caramelization.
Fresh thyme: Brings earthy brightness to the tart and enhances the fall flavors.

Salt and pepper: The classic seasoning duo to balance all the other elements.
Pie crust or tart shell: The buttery vessel that holds it all together and delivers satisfying crispness in every bite.

How To Make the Butternut Squash Caramelized Onion Tart

Step 1: Roast the Butternut Squash

Preheat your oven to 400°F. Toss cubed butternut squash in olive oil, salt, and pepper. Spread onto a baking sheet and roast for 25-30 minutes, or until golden and tender. Let it cool slightly.

Step 2: Caramelize the Onions

In a skillet over medium-low heat, add a splash of olive oil and sliced onions. Cook slowly, stirring occasionally, for 25-30 minutes until deep golden and fragrant. Don’t rush—low and slow is the key to developing their sweet richness.

Step 3: Prepare the Tart Base

Place your pre-made pie crust or tart shell into a tart pan. Press it gently into the sides and trim the edges. Pre-bake (blind bake) the crust at 375°F for 10 minutes to prevent sogginess.

Step 4: Mix the Custard Filling

In a mixing bowl, whisk together eggs, heavy cream, a pinch of salt, pepper, and a few thyme leaves. This creamy mixture brings everything together.

Step 5: Assemble the Tart

Layer roasted squash and caramelized onions into the tart shell. Dot with goat cheese or crumbled feta. Pour the egg mixture gently over the top, ensuring even distribution.

Step 6: Bake to Perfection

Bake the assembled tart at 375°F for 25-30 minutes, or until the custard is set and the top is slightly golden. Cool for a few minutes before slicing.

How to Serve and Store This Tart

Serve the Butternut Squash Caramelized Onion Tart warm or at room temperature. It pairs beautifully with a crisp green salad or a bowl of hearty soup for a cozy meal. This tart is ideal for brunch, holiday gatherings, or a satisfying vegetarian dinner.

To store leftovers, wrap the tart tightly or place slices in an airtight container. Refrigerate for up to 4 days. For best results, reheat in the oven at 300°F until warmed through—this helps preserve the crispness of the crust much better than a microwave.

You can also freeze this tart! Once baked and cooled, wrap it in foil and place in a freezer-safe bag or container. It keeps well for up to one month. Thaw in the fridge overnight before reheating.

Frequently Asked Questions

How do I know when the onions are fully caramelized?

They should be a deep golden brown and very soft. This usually takes 25-30 minutes over low heat. Stir occasionally to prevent burning.

Can I use store-bought pie crust?

Yes! A quality store-bought crust saves time and works wonderfully here. Just make sure to blind bake it before filling to avoid a soggy bottom.

Is there a vegan version of this tart?

Absolutely. Use plant-based cream and egg substitutes, and swap in vegan cheese. The texture will vary slightly but still be delicious.

What other cheeses work in this tart?

Feta, ricotta, or even shredded Gruyère can be used. Each will bring a different flavor profile, so feel free to experiment.

Can I prep this tart ahead of time?

Yes! Roast the squash, caramelize the onions, and even prepare the crust in advance. Assemble and bake fresh for best results, or bake the whole tart a day ahead and reheat.

What wine pairs well with this tart?

Try a crisp white wine like Sauvignon Blanc or a light red like Pinot Noir. Their acidity balances the richness of the tart.

Want More Savory Tart Ideas?

If you love this Butternut Squash Caramelized Onion Tart, here are more cozy and delicious recipes from Life With Olivia that bring flavor to your table:

Cheesy Spinach Stuffed Shells for a creamy, veggie-packed dinner.
Chicken Cordon Bleu Casserole when you’re craving comfort in every bite.
Mississippi Sin Quiche for a cheesy, protein-rich breakfast or brunch.

Taco Ranch Bites to spice things up with a fun twist on a classic.
Deep Dish Pizza Cupcakes if you’re looking for savory bites with a pizza flair.

Save This Recipe for Later

📌 Save this recipe to your Pinterest board so it’s ready when fall cravings hit! You can also find more daily recipes on my Pinterest: Life With Olivia on Pinterest.

Tried this tart? Let me know in the comments how it turned out for you. Did you use goat cheese or feta? Any fresh herbs you added?

Your variations and tips help make every bake better for everyone. Ask away if you have any questions—we’re in this kitchen journey together.

Butternut Squash Caramelized Onion Tart

Author: Olivia McKenney

Total Time: 1 hour 20 minutes
Yield: 6–8 slices
Diet: Vegetarian

Print Recipe

Description

This Butternut Squash Caramelized Onion Tart is a warm, savory, and cozy recipe perfect for autumn gatherings, holiday spreads, or a comforting vegetarian meal. Sweet roasted squash, jammy caramelized onions, and creamy goat cheese sit in a golden crust bound together by a luscious custard—simple ingredients elevated with seasonal charm.

Instructions

1. Preheat the oven to 400°F.

2. Toss diced butternut squash with 1 tablespoon olive oil, salt, and pepper. Spread on a baking sheet and roast for 25–30 minutes until tender and golden. Let cool slightly.

3. Heat 1 tablespoon olive oil in a skillet over medium-low. Add sliced onions and cook for 25–30 minutes, stirring occasionally, until caramelized and golden brown.

4. Fit the tart shell or pie crust into a 9-inch tart pan. Trim edges and blind bake at 375°F for 10 minutes to prevent sogginess.

5. In a mixing bowl, whisk together eggs, heavy cream, a pinch of salt and pepper, and thyme leaves.

6. Layer the roasted squash and caramelized onions evenly into the tart shell. Add crumbled goat cheese or feta over the top.

7. Pour the egg mixture gently over the filling.

8. Bake at 375°F for 25–30 minutes, or until custard is set and the top is lightly golden.

9. Let cool slightly before slicing and serving.