Caramelized Onion Butternut Squash Tart

Why You’ll Love This Recipe

I love this recipe because it brings together hearty autumn flavors with minimal effort. The butternut squash becomes perfectly caramelized in the oven, the onions turn soft and sweet, and the cheese adds richness to balance the vegetables. Using ready-made puff pastry makes the whole tart easy to assemble, while still giving a crisp, buttery crust. It’s one of those dishes that looks impressive but doesn’t require difficult steps.

Ingredients

(Here’s a tip: Check out the full list of ingredients and measurements in the recipe card below.)

1 medium butternut squash, peeled, seeded, and cubed (about 4 cups)
2 large yellow onions, thinly sliced
1 sheet puff pastry, thawed (or shortcrust pastry)
2 tablespoons olive oil, divided
1 tablespoon unsalted butter
4 ounces goat cheese, feta, or gruyère (crumbled or shredded)
1 teaspoon fresh thyme or 1/2 teaspoon dried
Salt and freshly ground black pepper, to taste
1 egg, beaten (for egg wash)

Optional
Balsamic glaze or honey for drizzling

Directions

Prep the squash

1. I preheat the oven to 400°F (200°C).

2. I peel, seed, and cut the butternut squash into 1/2-inch cubes.

3. I toss the squash with 1 tablespoon olive oil, thyme, salt, and black pepper.

4. I spread it on a baking sheet and roast for 20–25 minutes, flipping halfway, until tender and lightly browned.

Caramelize the onions

1. While the squash roasts, I heat 1 tablespoon olive oil and the butter in a large skillet over medium-low heat.

2. I add the sliced onions and a pinch of salt.

3. I cook the onions for 30–40 minutes, stirring occasionally, until they become deep golden and sweet.

4. If they start sticking, I deglaze the pan with a splash of water, wine, or vinegar.

Assemble the tart

1. I reduce the oven temperature to 375°F (190°C).

2. I roll out the puff pastry on a parchment-lined baking sheet.

3. I spread the caramelized onions over the pastry, leaving about a 1-inch border.

4. I layer the roasted squash evenly over the onions.

5. I sprinkle my choice of cheese on top.

6. I fold the edges of the pastry slightly inward to create a rustic border.

7. I brush the crust edges with beaten egg for a golden finish.

Bake

1. I bake the tart for 25–30 minutes, until the pastry is puffed, crisp, and golden brown.

Serve

1. I let the tart cool slightly before slicing.

2. I drizzle it with balsamic glaze or honey if I want a little sweetness.

3. I enjoy it warm or at room temperature.

Servings and Timing

This recipe yields 6 slices. Prep time takes about 20 minutes, roasting and caramelizing take around 55 minutes combined, and baking requires another 25–30 minutes. The total time is roughly 1 hour and 15 minutes.

Variations

I enjoy swapping in different cheeses such as blue cheese, cheddar, or gouda for a new flavor. Adding a handful of spinach or kale under the squash creates extra color and nutrients. For a more savory twist, I sometimes add a few sautéed mushrooms. If I prefer a crisper crust, I pre-bake the puff pastry for 8–10 minutes before adding the toppings.

Storage/Reheating

I store leftovers in an airtight container in the refrigerator for up to 3 days. To reheat, I warm slices in a 350°F (175°C) oven for about 10 minutes so the crust stays crisp. I avoid microwaving since it softens the pastry.

FAQs

Can I make this tart ahead of time?

Yes, I often caramelize the onions and roast the squash a day ahead. I assemble and bake the tart just before serving for the best texture.

Can I use frozen butternut squash?

I can, but I prefer fresh for better caramelization. If using frozen, I thaw and pat it dry before roasting.

Which cheese works best?

Goat cheese adds tang, feta offers a salty bite, and gruyère melts beautifully for richer flavor. I choose based on what I’m craving.

Can I make this tart without puff pastry?

Yes, shortcrust pastry or pie dough works, though the texture will be less flaky.

How do I keep the crust from getting soggy?

I make sure the onions and squash aren’t overly wet and avoid adding liquid. Pre-baking the crust for a few minutes also helps keep it crisp.

Conclusion

This Caramelized Onion Butternut Squash Tart is one of those dishes I return to again and again. Its mix of sweet vegetables, creamy cheese, and crisp pastry creates a beautifully balanced bite every time. I love how easy it is to prepare while still feeling like a special, seasonal meal. Whether I’m serving it as a main course or setting it out for guests, it always brings cozy, autumn-inspired comfort to the table.