Tart Bawang Karamel

Bahan-bahan (6 porsi)

• 2 sheets Puff Pastry, (thawed in the fridge overnight)
• 4 cups Sweet Yellow Onions, (sliced)
• 1 tbsp Olive Oil
• 2 tsp Brown Sugar
• 1/2 tsp Kosher Salt
• 1 cup Gruyere Cheese, (shredded )
• 2 tsp Fresh Thyme, (destemmed and minced)
• 2 tbsp Heavy Cream