For an elegant appetizer or light dinner, you can’t do better than these simple tarts. A sweet and savory mix of cooked New York apples and caramelized onions tops store-bought puff pastry spread with crème fraîche, a thick and creamy dairy product similar to sour cream. When it comes to caramelizing onions, remember low and slow is the key to bringing out the onions’ naturally occurring sugars without scorching.
