The Cozy Fall Tart You Didn't Know You Needed: Caramelized Onion, Apple & Cheddar

Fall just got a lot tastier with the arrival of the Caramelized Onion, Apple & Cheddar Tart—a dish that transforms everyday ingredients into a cozy, culinary celebration. Frozen puff pastry serves as the perfect base for this showstopper, loaded with layers of jammy caramelized onions, crisp apple slices, and sharp cheddar cheese.

This tart isn’t just about combining flavors; it’s about creating a symphony of tastes and textures. The caramelized onions bring a deep, rich sweetness, while the tart apples add a refreshing bite. Sharp cheddar cheese delivers a punch of savory goodness, and a drizzle of honey ties everything together with a touch of sweetness. Fresh thyme adds a hint of herbal warmth, making each bite a comforting nod to autumn’s best.

If you’ve never tried the sweet-savory combination of apples and cheddar in a pastry, get ready for a revelation. This unlikely pairing turns into a harmonious blend that’s as delightful as it is unexpected. So, get your oven ready and dive into this autumnal treat—your taste buds will thank you.

Caramelized Onion, Apple, and Cheddar Tart Photo: The Kitchn

Caramelized Onion, Apple & Cheddar Tart

Recipe from The Kitchn

Prep time: 20 minutes to 30 minutes

Cook time: 1 hour 10 minutes to 1 hour 15 minutes

Serves: 8 to 12

Ingredients

• 1 (14- to 17-ounce) package frozen puff pastry (preferably all butter)

• 3 large yellow onions

• 4 tablespoons (1/2 stick) unsalted butter

• 6 ounces sharp cheddar cheese, preferably white (about 1 1/2 cups shredded)

• 10 to 12 sprigs fresh thyme

• 1 large egg

• 1/4 cup low-sodium vegetable or chicken broth, or water

• 1 teaspoon apple cider vinegar

• 1 teaspoon kosher salt, plus more as needed

• All purpose flour, for dusting

• 1 medium apple, such as Honeycrisp or Pink Lady

• 2 tablespoons honey, plus more for serving

• Red pepper flakes (optional)

Instructions

1. Thaw 1 package frozen puff pastry in the refrigerator according to package directions.

2. Thinly slice 3 large yellow onions (about 7 cups). Melt 4 tablespoons unsalted butter in a Dutch oven or heavy-bottomed pot over medium heat. Add the onions and stir them gently to coat with the melted butter. It will seem like a lot, but they will cook down significantly.

3. Cook, checking on them every 5 minutes and stirring and scraping up any browned bits on the bottom with a wooden spoon, until deep brown, jammy, and caramelized, about 35 minutes total. If the onions start to get too dark, reduce the heat.

4. Meanwhile, line a rimmed baking sheet with parchment paper. Arrange a rack in the middle of the oven and heat the oven to 400°F. Grate 6 ounces sharp cheddar cheese on the large holes of a box grater (about 1 1/2 cups). Pick the leaves from 10 to 12 fresh thyme sprigs (about 1 1/4 teaspoons) and finely chop. Whisk 1 large egg in a small bowl with a fork until broken up.

5. When the onions are ready, add 1/4 cup low-sodium chicken or vegetable broth or water and scrape up any browned bits from the bottom of the pot. Add 1 teaspoon apple cider vinegar and 1 teaspoon kosher salt and stir to combine. Taste and season with more kosher salt as needed. Remove the pot from the heat.

6. Slide the parchment onto a work surface and lightly dust with all-purpose flour. Unfold the puff pastry onto the parchment (if your package has 2 sheets, place them side by side, slightly overlapping, so that they fit the baking sheet). Using a floured rolling pin, roll it into a rectangle about the size of the baking sheet. Slide the puff, still on the parchment, onto the baking sheet.

7. Brush the edges with the egg to form a 1-inch border. Carefully roll about 1/2-inch of each side in on itself toward the center to form the outer rim of the tart. Prick the pastry all over with the tines of a fork. Brush the rim with the egg. Bake until light golden brown and slightly puffed, 10 to 15 minutes. Meanwhile, halve, core, and thinly slice 1 medium apple (2 cups).

8. Remove the baking sheet from the oven. If the pastry has puffed up, gently press down with a spoon to deflate. Transfer the onions onto the tart and spread into an even layer, stopping when you get to the folded edges. Sprinkle with half of the cheese. Arrange the apple slices evenly over the cheese. Sprinkle with the remaining cheese and thyme. Drizzle with 2 tablespoons honey, and sprinkle with red pepper flakes if desired.

9. Bake until the edges are puffed and the bottom is crisp and golden-brown, 18 to 30 minutes more. Let cool for at least 5 minutes. Transfer onto a cutting board. Cut and serve warm with more honey if desired.