Then, I sliced a few strawberries and a nectarine and layered them with the puffed pastry and vanilla yogurt. Of course you can choose any other fruit and yogurt flavor: it's your food, do with it what you wish :) For example, I think it would be great to use Greek yogurt. And actually, since puffed pastry is not overly sweet, you can make these Napoleons using savory flavors!
This was a very simple dessert to make. I was almost as excited about taking pictures of it as eating it. Speaking of eating, it'd be pretty impossible to eat the Napoleon as is: it's just too high and unstable. The pictures below, thus, show the de-constructed Napoleon: a bit messy, but still delicious! The sweetness of the fruit was offset by the slightly tangy yogurt, and of course the puffed pastry added a superb crunch and butter taste.
In case you just don't feel like building towers with your food, simply combine fruit and yogurt in a bowl and add a few squares of puffed pastry: I doubt anyone will say no to this fresh summery dessert.