Gruyere & Caramelized Onion Tarts

Directions

1. In a large skillet, saute onion in oil and butter until softened. Reduce heat to medium low; cook, uncovered, 40 minutes or until deep golden brown, stirring occasionally. Add garlic; cook 1 minute longer. Stir in salt and pepper.
2. Unfold each puff pastry sheet onto an ungreased baking sheet. Using a knife, score decorative lines around the edges of each sheet. Spread onion mixture to within 1/2 in. of edges. Sprinkle with cheeses and thyme.
3. Bake at 400° for 12-15 minutes or until golden brown. Cut each tart into 12 pieces. If desired, top with additional fresh thyme and Parmesan cheese. Serve warm.