Butternut Squash and Caramelized Onion Tart

More fall flavors are featured in this butternut squash tart with caramelized onion. This makes a great Thanksgiving appetizer and is surprisingly easy to prepare thanks to frozen puff pastry sheets. Feel free to switch it up with a different variety of cheese. I used fontina and a cinnamon-dusted toscana cheese (similar to parmesan) from Trader Joe's. I know, cheese and cinnamon? It sounds like a strange combination, but I assure you that it pairs very well with the squash. A few fried sage leaves on top add color and earthy flavor to this delicious squash tart.

Ingredients 

2 square sheets of frozen puff pastry (I used Trader Joe's)

1 small butternut squash

1 yellow onion, sliced into 1/4-inch rings

2 tablespoons olive oil

2 tablespoons butter

1 teaspoon Herbes de Provence

Salt and pepper

1 egg, beaten

1 cup shredded fontina cheese

1/2 cup grated toscana cheese (try the cinnamon-dusted variety from TJ's...parmesan will also work here)

Sage leaves

Oil for frying

Directions

Pre-heat oven to 400 degrees F. Cut the squash in half lengthwise and peel the outer layer of skin. I just used the neck portion of the squash so that my pieces were the same size. Using a sharp knife or a mandolin slicer, slice the squash into uniform 1/4-inch slices. On a foil lined pan, toss the squash with the olive oil and season with salt, pepper, and 1/2 teaspoon Herbes de Provence. Roast in the oven for about 10 minutes. Remove and let cool slightly.

While the squash roasts, caramelize your onions. In a sauté pan over medium heat, melt two tablespoons of butter and add the onions. Season with salt, pepper, and the other 1/2 teaspoon Herbes de Provence. Cook, stirring occasionally, until the onions are caramelized and soft. While the onions cook, prepare your pastry.  Place on of the squares on a parchment-lined baking sheet. Cut four two-inch strips from the second piece of pastry and place the strips around the outer edges of the pastry square. 

To assemble the tart, place the caramelized onions on the pastry dough and top with the shredded fontina. Arrange cooled squash slices in a concentric layered pattern on top of the cheese. Brush the edges of the pastry with the beaten egg. Bake in the pre-heated oven for 20-25 minutes. While the tart is baking, fry your sage leaves. In a small saucepan over medium high heat, warm some olive oil. When the oil is hot, add the sage leaves and fry until they are crispy (about one minute). When the tart is finished baking, remove from the oven and top with the shredded toscana cheese and the fried sage leaves. Serve warm or at room temperature.