As promised here's the recipe:
1 lb asparagus
1.5 cups chicken stock
4 tbs chopped shallots
1 cup milk or1/2 & 1/2
2.5 tbs butter
2 tbs flour
1/3 cup shelled pistachios
Salt and pepper to taste

Throw the asparagus into a pot with 2 cups water. Cover and cook
until just tender. Pour off 1 cup water and save. Drain the asparagus
and set aside. Put 1/2 tbs butter in the pot and cook shallots until
just starting to become transparent. Put the asparagus, the reserved 1
cup of asparagus cooking water, and the chicken broth in the pot with
the shallots. Add the pistachios. Cook for a few minutes to soften the
nuts a little. Using a blender of some sort, I like stick blenders,
puree the soup. Make it as smooth as possible. Now put the soup
through a strainer. If pureed well enough almost no fibers will be
left in the strainer. Any fibers in the soup will ruin the texture, so
strain well and re-puree if needed. Melt the remaining butter in a
small pot, add the flour to make a roux, and cook until light brown.
Browning the roux really adds to the good flavor of the soup. Pay
attention, stirring often so it doesn't burn. Add the milk or 1/2 &
1/2 slowly using a whisk to stir so there will be no lumps. Cook until
it just comes to a boil and thickens, stirring constantly. Add to the
pureed asparagus and heat through. Serve with roasted garlic sourdough
bread.
Though I haven't tried it yet I think a little cayenne sprinkled on
top would be good.
In the interest of full disclosure you should know that my recipe
above is based on a recipe in the Fannie Farmer Cookbook, twelfth
edition, copyright 1980. I have changed it some from the book but the
basic recipe comes from the book and I need to give credit where
credit is due.
Speaking of cookbooks, I have several because I like to cook and
I'm the cook in our house. And the Fannie Farmer Cookbook is one of my
favorites. I actually have two different editions and they differ from
each other in many ways.
Eric