Cream of Portabella Soup (lacto-ovo vegetarian)

Why I Love This Recipe
This is a recipe one of my friends gave me when I became a vegetarian :)
Ingredients You'll Need
5 Tbsp melted butter
3 Tbsp flour
3/4 cup chopped onion
6 oz. portabella mushrooms, 1" pieces
Salt
2 cups milk
2 cups heavy cream
1/4 tsp. fresh ground black pepper
1/4 tsp dried thyme
2 Tbsp Marsala or sweet sherry
2 oz. Roquefort or blue cheese (optional)
Directions
Heat 3 Tbsp of butter in small saucepan over med. heat.
Add the flour and stir constantly until roux forms.
Continue to stir and cook for another minute, until flour cooked.
Remove from heat and set aside.
Place remaining 2 Tbsp. of butter in med. saucepan over med. heat.
Add onion and saute until golden, about 2 minutes.
Add 2 Tbsp. of water to pan and then add mushrooms.
Salt lightly, reduce heat, and cover.
Let pan sit over heat for 10 minutes.
Remove lid and add the milk, cream, pepper and thyme.
Increase heat and bring almost to boil -- when bubbles from around the edge of the pan.
Stirring, add butter-flour mixture to milk.
Add marsala/sherry and stir with a whisk over med. heat until soup thickens - 3 to 4 minutes.
Adjust for salk.
Ladle into bowls and sprinkle with optional cheese.