In a large saucepan, ADD mushrooms, broth, onion and thyme; COOK until mushrooms tender, 10-15 minutes.
In blender, PUREE the mixture, leaving some chunks of vegetable in it; SET aside.
In the sauce pan, MELT the butter; WHISK in flour until smooth; ADD salt, pepper, half and half and vegetable puree.
BRING soup to boil, STIRRING constantly; COOK until thickened; ADJUST seasoning to taste, STIR in sherry.
Per Serving (excluding unknown items): 151 Calories; 11g Fat (65.1% calories from fat); 4g Protein; 9g Carbohydrate; 1g Dietary Fiber; 30mg Cholesterol; 358mg Sodium. Exchanges: 0 Grain(Starch); 0 Lean Meat; 1 Vegetable; 0 Non-Fat Milk; 2 Fat.