I called this a French onion tart not because it is necessarily “French” but more so because it tastes like a thick cheesy bowl of French onion soup, in tart form of course. The caramelized onions are sweet, the Swiss cheese is a little tangy and the puff pastry crust is buttery. Everything I love about a French Onion soup! We made a version of this tart in class a few weeks ago and I just knew I would have to come home and make it. The result? An INCREDIBLE savory tart loaded with flavor. I served this along side beef with a mushroom sauce and it was the perfect accompaniment. You could serve this with a salad for a vegetarian dinner as well. I’m also aware that this is in a pie pan and not a tart pan but that’s because I didn’t own a tart pan! Can you believe it? Well I do now! Thank you Calphalon outlet. 🙂
This recipe isn’t difficult, it just takes a little time. You know what though? Sometimes that is okay. Especially when the result is this delicious!
French Onion Tart
1 sheet of puff pastry
1 1/2 cups dried beans or uncooked rice for blind baking (these will not be eaten!)
2 tablespoons olive oil
2 tablespoons unsalted butter
2 large sweet onions, peeled and sliced thinly into half moons
1/2 teaspoon salt
4 sprigs of fresh thyme (or about 1/2 teaspoon dried thyme – more to taste)
3 cloves of garlic, minced
1/2 cup heavy cream
1 egg, beaten
5-6 oz Swiss cheese, shredded (fresh is really important here, not the bagged stuff)
Preheat oven to 375. Using a 8 inch pie plate (or tart pan) as a guide, invert pie pan on puff pastry. Using a sharp knife, cut around the outline of the pie pan. Set puff pastry scraps aside.* Lightly spray pie pan, lay puff pastry inside pie pan and press to form to pan. Fold over any excess dough around the top inside the pan. Line the dough with parchment paper that has been cut to fit inside the dough and fill the pie pan with dried beans or uncooked rice. This will allow the dough to partially cook without over browning or getting an unruly shape. Bake until crust is lightly golden, about 10 minutes. This will depend on your oven. Once slightly cool, remove parchment and beans (these can be saved for another time). Set aside.
While your crust is cooling (or baking if you are good at multitasking), heat butter and oil in a large skillet over medium low heat. Add onions, thyme leaves (removed from sprigs), salt and pepper to taste. Allow to slowly caramelize until onions are sweet and golden brown (about 10 to 15 minutes) stirring frequently. Add the garlic and cook for 5 minutes further. Check seasonings for salt and pepper. Adjust as necessary. Remove from heat, transfer onion mixture to a bowl and allow to cool 5 minutes. Once slightly cooled, add Swiss cheese, egg and cream. Stir to combine. Pour into pie shell, smooth top with spatula. Bake at 375 for 15-20 minutes until tart is mostly set in the middle and golden on the top. This may take up to 25 minutes depending on your oven.
Allow to cool for 10 minutes before serving.
* Looking for something to do with the leftover puff pastry scraps? Don’t roll them up, leave them flat, folding in half if necessary and roll out evenly. Using a pizza cutter or sharp knife cut strips of the puff pastry and twist the strips to form a twisted bread stick of sorts. Season with salt and maybe a little garlic powder and bake at 375 until puffed and golden.