Caramelized Onion Tartlets

Caramelized Onion Tartlets

1 can crescent roll dough
2 tablespoons butter
1 tablespoon olive oil
2 large onions, very thinly sliced
1 bay leaf
1 teaspoon ground thyme
1/2 teaspoon sugar
1/2 teaspoon balsamic vinegar
Salt and black pepper
1/2 lb. Swiss cheese, shredded
1/2 lb. mozzarella cheese, shredded

Preheat oven to 350 degrees.
Using a rolling pin, gently roll the dough out on a lightly floured surface. Use a 2 1/2-inch to 3-inch round cookie cutter to cut the dough into circles. Place each circle into the muffin tins pressing down gently. Place tin in the oven and bake for about 8 to 10 minutes or until browned slightly. Remove from the oven.
Meanwhile, in a large skillet over medium-high heat, heat the butter and olive oil. Add the onions, sugar, balsamic vinegar and bay leaf, season with the thyme, salt and pepper. Cook the onions until caramel colored, 20 to 25 minutes. Discard the bay leaf after the onions have cooked.
Turn the broiler on to low.
Place about a tablespoon of the cooked onions into each of the dough cups. Top the onions with both cheeses and place the tartlets under the hot broiler. Broil until the cheese is bubbly and golden.