Instructions

1. 1
   In a large pot over medium heat, melt one stick of the butter.
2. 2
   Add ½ cup of the flour, stirring constantly, to form a roux.
3. 3
   Cook, continuing to stir constantly, until roux takes on a pale blond color, about 5 minutes.
4. 4
   Slowly stir in the beef stock.
5. 5
   Bring to a boil, stirring frequently.
6. 6
   Reduce heat to a simmer.
7. 7
   In a large saucepan over medium-high heat, melt the remaining stick of butter with the olive oil.
8. 8
   Add the portobellos, shiitakes, and button mushrooms and sauté until mushrooms are moist and tender, 5–10 minutes.
9. 9
   Remove pan from heat and dust mushrooms with the remaining ½ cup of flour, tossing gently to incorporate flour.
10. 10
    Combine mushrooms and beef stock in the large pot.
11. 11
    Stir in the sherry.
12. 12
    Cook, stirring occasionally, until flavors are melded and soup thickened slightly, about 10 minutes.
13. 13
    Serve hot.