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Turn your baking routine on its head with this upside down leek tart! Sweet, caramelized leeks meet a buttery, flaky crust baked to golden perfection. And with our foolproof step-by-step photos, it’s surprisingly easy to make and guaranteed to impress.
save this recipe!You’ll Love This Tart
Leeks in a tart? Oh… heck, yes. This upside down leek tart transforms that bunch of leeks sitting in your fridge into something savory, buttery, and downright irresistible.
It’s packed with caramelized goodness (without actually being complicated to make). I’ll admit—I was skeptical at first, but I couldn’t have been more excited about how it turned out!
Leeks and parmesan go in first, puff pastry goes on top, and it’s all baked until golden perfection. Flip it over, slice it up, and just like that—creamy, cheesy, veggie-packed deliciousness. Perfect for brunch, dinner, or when you just want to feel a little extra without the extra effort.
Reader rating
“I’ve made this fantastic recipe twice over the holidays and it was a hit both times!” —Marilee
Here’s what You need
The ingredient list is pretty short and sweet for a recipe as fancy (looking) as this leek tart. Jump to the recipe card for exact measurements—this is an overview!
- Leeks: We’ll use thin leeks as the base of our tart. (I recommend thin so that they cook properly with the other ingredients.)
- Butter: Next, grab some unsalted butter (for better control over the sodium content of this recipe).
- Seasonings: Salt and pepper bring out the crust’s buttery flavors, while sugar helps caramelize the leeks. And garlic and thyme complement each other beautifully! (Feel free to use rosemary or oregano.)
- Cheese: We’ll add shredded parmesan for all of the cheesiness. For strict vegetarians, look for a vegetarian-friendly parmesan brand at your local healthy grocery store (like Whole Foods!).
- Crust: You’ll need 1 thawed puff pastry sheet for the top (well, technically, the bottom) of the tart.
- Egg: Finally, we’ll brush the top of the pastry with an egg wash to make the crust golden brown and shiny!
Making This French Tart Is Actually Easy
This upside down leek tart is one of those deceivingly simple recipes. Jump to the recipe card for the full printable instructions!
Step 1: Prepare The Leeks
Remove the puff pastry from the freezer and let it thaw. Preheat the oven to 400°F (204°C). Remove the dark tops from the leeks and cut the roots off.
Step 2: Cook The Leeks
Heat the butter in a large cast-iron or oven-safe skillet over medium heat. Add the leeks, cover, and cook, flipping occasionally, until they’re soft. Once cooked, remove the leeks from the pan.
Step 3: Assemble The Tart
Add the remaining butter, sugar, salt, pepper, garlic, and thyme to the pan. Stir and cook until melted, then remove from the heat. Arrange the leeks on top of the butter mixture, then sprinkle parmesan over the leeks.
Step 4: Add The Pastry
Gently place the thawed puff pastry on top of the leeks. Use clean scissors to trim the corners, then tuck in the edges. Whisk an egg and brush it on top, then cut a few slits in the top of the pastry to allow steam to escape.
Step 5: Bake The Dish
Bake for 35 to 45 minutes until the top of the tart is golden brown.
Step 6: Flip It!
Let the tart cool slightly, then gently work a small knife or rubber spatula around the edge. Place a plate or cutting board on top of the pan, then flip the whole contraption in one swift motion. Cut into 6 slices and serve!
Got More Leeks?
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Easy Upside Down Leek Tart Recipe (Step-By-Step)
Ingredients
- 6 thin leeks
- 4 Tbsp unsalted butter, divided, 56 g
- 1 tsp sugar
- ¼ tsp each salt and pepper
- 2 cloves garlic, minced
- 1 Tbsp fresh thyme leaves, roughly chopped
- ½ cup shredded parmesan, 40 g
- 1 puff pastry sheet, thawed
- 1 egg
Instructions
- Prep: Remove puff pastry from the freezer and let it thaw. Preheat the oven to 400°F (204°C). Remove the dark tops from the leeks. Cut off the roots, getting as close to the root as possible (we're trying to keep the leaves all attached). Remove the tough outer leaves. Gently rinse under water to remove dirt from between the leaves.
- Soften: Heat 2 Tbsp of the butter in a large cast-iron (or oven-safe) skillet over medium heat. Add the leeks, cover, and cook, flipping occasionally, until they're soft, about 15 minutes (you may need to work in batches). If the leeks begin to brown, lower the heat. Remove leeks from the pan.
- Assemble: Add the remaining butter, sugar, salt, pepper, garlic, and thyme to the pan. Stir and cook until melted, then remove from the heat. Arrange leeks on top of the butter mixture, packing in as many as possible. You may need to cut them to fit in the smaller spaces! Sprinkle parmesan over the leeks.
- Top: Gently place the thawed puff pastry on top of the leeks. Use clean scissors to trim the corners to fit it in the pan. Tuck in the edges. Whisk an egg and brush it on top. Cut a few slits in the tops of the pastry to allow steam to escape during cooking.
- Bake: Bake for 35 to 45 minutes until the top is golden brown. If it browns too quickly, gently cover the tart with aluminum foil.
- Flip: Allow the tart to cool slightly, then gently work a small knife or rubber spatula around the edge to loosen the crust from the pan. Place a plate or cutting board on top of the pan, then flip the whole thing in one quick motion. The tart should come loose from the pan and end up on the plate. If any leeks stick to the pan, simply rearrange them back onto the tart. Cut into 6 slices and serve!
Notes
Nutrition
Nutrition information calculated by Sarah Bond, degreed nutritionist.
did you make this?Leave a comment below and tag @liveeatlearn on social media! I love seeing what you’ve made!
Do you think this would work with a packaged pie crust?
It won’t be quite as flaky without puff pastry, but it should work well!
I tried it and it was delicious! Definitely going to give it a go with puff pastry next time!
I’ve made this fantastic recipe twice over the holidays and it was a hit both times!
The first time I made it with leeks as described above. I struggled to make it as pretty as the pictures above because the leeks seemed to need to be broken up slightly in order to cook through.
The second time I went rogue and used roasted acorn squash and sauteed tomatoes instead of leeks. It worked really well! My guests recommended further adding a drizzle of balsamic reduction and a fresh arugula topping post-baking.