Upside Down Leek Tart (with Parmesan and Thyme!) (2024)

Get creative with your leeks and whip together this Upside Down Leek Tart. It’s the perfect late afternoon bite and creates 6 servings!

Did you know leeks can be used in a cheesy, savory tart? I know, it may sound complicated, but the truth is that it’s such a delicious way to cook leeks.

I was skeptical too, and I couldn’t have wound up more excited about how it turned out! This upside down leek tart is made by adding leeks and parmesan to a skillet, and then adding a puff pastry on top! It’s then baked and sliced like a pizza or pie!

The result is a creamy, cheesy, dish perfect for enjoying when you want something indulgent but still need to sneak in your veggies.

Here’s what you’ll need

For a recipe as fancy (looking) as this leek tart, the ingredients list is pretty simple!

• Leeks: First, you’ll need 6 thin leeks. I recommend thin so that they cook properly with the other ingredients.
• Butter: Next, grab 4 tablespoons of unsalted butter and divide it for using at two points in the recipe.
• Seasonings: Salt and pepper bring out all the buttery flavors of our leeks and crust, while sugar helps to caramelize the leeks. Helloooo flavortown.
• Flavorings: Garlic and thyme compliment the thyme beautifully! Feel free to throw in more. to suit your taste (rosemary, oregano, or even an Italian spice blend would work well here!)
• Cheese: Next, add ½ cup of shredded parmesan for all of the cheesiness. For strict vegetarians, look for a vegetarian parmesan brand at your local healthy grocery store (like Whole Foods!).
• Pastry: You’ll need 1 thawed puff pastry sheet for the top (well, technically the bottom) of the tart.
• Egg: Finally, 1 egg will be used as a wash on top of the pastry to make the crust golden brown and shiny!

How to make an upside down leek tart

This is one of those recipes that’s deceivingly simple. Essentially, all we’re doing is cooking the leeks, then placing them in a skillet and topping with puff pastry!

Step 1: Prepare
Remove the puff pastry from the freezer and allow it to thaw. Preheat the oven to 400°F (204°C) and remove the dark tops from the leeks. Cut off the roots, cutting as close to the root as possible while keeping the leaves all attached.

Remove the tough outer leaves, then gently rinse under water to remove dirt from between the leaves (leeks are dirty fellas!). I sometimes like to let them soak in a bowl of water to really get all that dirt out.

Step 2: Cook the leeks
Heat 2 tablespoons 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. It should take about 15 minutes, and you may need to work in batches. If the leeks begin to brown, lower the heat. 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 it’s all melted, then remove from the heat. Arrange the leeks on top of the butter mixture, packing in as many as you can. You may need to cut them to fit in the smaller spaces!

Sprinkle parmesan evenly over the leeks. If you’re feeling adventurous, you could dollop on even more cheeses or flavors here (like ricotta cheese, goat cheese, or Dijon mustard).

Step 4: Add the pastry
Gently place the thawed puff pastry on top of the leeks. Use clean scissors to trim the corners so that it fits well in the pan. 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 during cooking.

Step 5: Bake the dish
Bake for 35 to 45 minutes, or until the top of the tart is golden brown. If it browns too quickly, gently cover the tart with aluminum foil.

Step 6: 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 contraption in one swift motion. The tart should come loose form 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!

How to store leftover leek tart

Have extras? Sweet! This dish tastes just as good (if not better) the second day. Keep it in an airtight container in the refrigerator and enjoy within 2 to 3 days. You can microwave to reheat, though the crust is best if reheated slowly in a pan on the stove.

Hungry for more?

From fried cauliflower and Spanish rice to fried tofu and gyros, there’s a reason these are popular favorites!

• Air Fryer Cauliflower
• Spanish Rice and Beans
• Crispy Air Fried Tofu
• Roasted Chickpea Gyros