This recipe is so simple, healthy, and yummy! It is based on one I found in Gourmet Magazine (May 2007). They recommend using morel mushrooms, but the recipe works just as well with any kind of mushroom. If you don't have tarragon, you can use fresh basil instead. If you can find the white asparagus, you can use 1 pound of the white asparagus and one of the green for a lovely presentation. If you do use the white asparagus, cook it for a little longer (about 5 minutes) in a separate pot.