During Lent this year, my daughter gave up meat (as she always does) and forty days of meals without beef, chicken, pork etc. can be quite a struggle when the rest of the family "want meat". What is a mom to do but pull out the big guns and get a little craftier. The big guns were my library of cookbooks that usually just sit there gathering dust but in cases like these, I'm glad those babies are there for back-up. Some of my meatless 'creations' got a few thumbs down but this Caramelized Onion, Apple and Gruyere tarts were a big hit! The lightness of the puff pastry balances out the richness of the caramelized onion and Gruyere, they compliment each other perfectly! This recipe makes about 32 tarts and believe it or not, there are never any left when they are put on the table!
2 tablespoons vegetable oil
1 1/2 lb. yellow onions, halved and thinly sliced
1 teaspoon kosher salt, plus more, to taste
2 tablespoons unsalted butter
1 lb. tart apples, peeled and sliced 1/8 inch thick
1 teaspoon sugar
1 1/2 oz. aged Gruyere cheese, grated
2 tablespoons chopped fresh chives
1 teaspoon chopped fresh thyme
1/8 teaspoon freshly ground pepper, plus more, to taste
1 package (1 lb.) frozen puff pastry dough, thawed
In a large fry pan, warm the vegetable oil over medium heat. Add the sliced onions and 1 teaspoon kosher salt and saute for about 30 minutes, stirring occasionally, until the onions are golden brown.
Transfer into a large bowl and let the filling cool to room temperature.
Position 1 rack in the upper third and 1 rack in the lower third of an oven and preheat to 400°F. Line 2 baking sheets with parchment paper.
In the same pan you used for the onions, melt the butter over medium heat. Add the sliced apples and sugar and stir to coat the apples. Continue stirring for about 10 minutes until the apples are just starting to caramelize and have softened. Transfer into the bowl with the onions and stir in the chives, thyme, cheese and the 1/8 teaspoon pepper.
Cut the puff pastry into 2-inch squares and place on the baking sheets, spacing the squares about 1 inch apart. In a small bowl, beat the egg and add about 2 teaspoons of water.
Brush the pastry squares with the egg mixture and place a heaping 1 tablespoon of filling in the center of each square. Season with salt and pepper.
Bake, rotating the baking sheets from top to bottom and front to back halfway through baking, until the pastry is crisp underneath and golden brown on top, which should take about 25 minutes. Transfer the baking sheets to wire racks and let the tarts cool to room temperature before serving.
Makes about 32 tarts.