Caramelized Onion and Gorgonzola Tart

These make fantastic appetizers, and they are very easy to make. I've trotted these out at numerous events and have yet to have leftovers. I adapted the recipe from this one from Pepperidge Farm, which, not coincidentally, makes puff pastry. I've yet to try making puff pastry from scratch--it doesn't seem worth the headache, somehow. If you've tried it and have some advice for me, I'm very willing to hear it!

EDIT: I recently tried this recipe with shredded Gruyère in place of the Gorgonzola. I highly recommend it--the Gruyère melts really well, and its nuttiness sets off the sweetness of the caramelized onions. The Gorgonzola cheese is also good, just spicier...but, packaged puff pastry comes in packs of two sheets, so why not try both?

Thawing time: 40 minutes
Prep time: 10 minutes
Cook time: 15 minutes
Bake time: 20 minutes
Cooling time: 5 minutes

Ingredients
1 sheet of store-bought puff pastry
3 tablespoons vegetable oil
1-2 sweet onions, thinly sliced into half moons (total 2 cups uncooked)
1 cup crumbled Gorgonzola cheese (pre-crumbled saves time, but the pre-crumbled chunks can be too small and are usually a little drier than cheese you crumble yourself)
flour (for rolling out pastry)

Optional ingredients:
Chives, parsley, basil, or other herbs
salt and pepper (to taste)
1½ teaspoons brown sugar


Hardware
skillet
wooden spoon
baking sheet
rolling pin
grater (if using Gruyère)
fork
wire rack

Directions
1. Thaw the pastry sheet at room temperature for 40 minutes or until it's easy to handle. Heat the oven to 400°F. Line a baking sheet with parchment paper or spray with vegetable cooking spray.

2. Heat the oil in a 12-inch skillet over medium heat. Add the onion and cook for about 15 minutes or until dark golden brown, stirring often. Season to taste (brown sugar and/or salt) and let cool.

3. Unfold the pastry sheet on a lightly floured surface. Roll into a 12-inch square. Place on the prepared baking sheet. Brush the edges of the square with water. Fold over the edges ½ inch on all sides, pressing firmly with a fork to form a rim. Prick the pastry thoroughly with a fork.

4. Spread the onion mixture as evenly as possible over the pastry crust. Top with the Gorgonzola cheese. (You can add herbage on top here if you choose--chives, parsley, or even basil will work.)

5. Bake for 15-20 minutes or until golden and bubbly. Cool for 5 minutes on a wire rack. Cut into approximately 3 x 2-inch rectangles. Serve warm.