This is from the New York Times, all I added was the Spring Onions, which give it an extra flavor boost. Make sure to us puff pastry that is made only with butter.
Heat the oven to 425.
Trim 1 or 2 Spring Onions. Cut the leaves off the shanks and reserve them. Slice the shanks in half lengthwise and then thinly slice in half rounds. You want about a Cup. Chop the leaves but keep them separate.
In a bowl, mix together 1 egg, 1 C. of goat cheese, 1/2 t. salt, and the onion slices. Add fresh herbs if you like. Use a whisk to beat in 1 C. creme fraiche or half and half.
On a floured surface, roll out a sheet of puff pastry into a rectangle 11 x 13 inches and 1/8″ thick. Use a knife to score the edges, then spread the egg/cheese mixture out over it.
Snap the bottoms off 1 bunch of asparagus, then slice the spears in half lengthwise. Press lightly into the cheese mixture. Brush with olive oil and sprinkle with salt and some shaved parmesan. Sprinkle the chopped onion tops over everything.
Bake until the pastry is puffed and golden, 25 to 30 minutes.