Bring 4 cups chicken stock to a simmer in medium saucepan.
Add asparagus, cover and cook over medium heat,around 10 minutes.Or until asparagus is tender.
In another saucepan melt butter in low heat.
Saute' onion and add mushroom then add the flour.
Add this mixture to the asparagus and cover until mushroom is soft. Add 1 cup evaporated milk and season with garlic salt.
Garnish with parsley,basil or mint. Serve hot
NOTE: You can add salt or pepper, but I like my Asparagus and Mushroom soup without salt.