Caramelized onions, crunchy walnuts and sharp cheese are a winning combination in these beautiful tartlets. They’re simple to make for a cocktail party or holiday gathering, especially if you cook the onions ahead of time.
Makes about 24 pieces
1 12 x 18-inch rectangle Grand Central U-Bake Classic Puff Pastry, defrosted overnight in fridge or for 1 1/2 hours on counter
1 tablespoon unsalted butter
1 tablespoon extra virgin olive oil
1 large sweet onion, thinly sliced
1/2 teaspoon kosher salt
1/2 teaspoon freshly ground pepper
1 tablespoon chopped fresh thyme
1/2 cup chicken, vegetable or beef broth
2 tablespoons sherry
2 tablespoons heavy cream
3/4 cup walnuts, roughly chopped
1 cup shredded gruyere cheese
Prepare puff pastry
Defrost puff pastry overnight in the refrigerator or on the counter for about 1 ½ hours. Unroll sheet, cut into 2 1/2 to 3-inch squares and transfer to two parchment-lined baking sheets. Refrigerate. Return remaining pastry to freezer for future use.
Preheat oven to 375 degrees.
In a large saute pan, heat butter and olive oil until bubbling. Add onion, salt and pepper and reduce heat to medium low. Continue cooking, stirring frequently, until onions soft and beginning to caramelize, about 10 minutes. Add broth, sherry and fresh thyme and continue cooking until liquid is almost evaporated and onions are very soft. Stir in cream, remove from heat and set aside.
Place 1 tablespoon caramelized onion, a few pieces of chopped walnut and a pinch of shredded cheese in the center of each square. If making ahead of time, chill until ready to bake.
Bake and serve
Bake on center rack of preheated oven for about 20 minutes, until pastry is puffy and deep golden brown, rotating baking sheets halfway through cooking. Serve immediately or let cool to room temperature.