1-1/2 oz unsalted butter
1/2 c diced onion
1-1/4 lbs fresh mushrooms, caps removed, cleaned and sliced
6 c TURKEY STOCK
1/4 c all-purpose flour
1/2 c cold water
2 tsp poultry base
1/2 tsp ground white pepper
1-2/3 c 2% milk
3/4 c sour cream
2 tbsp fresh parsley, chopped
1 lb COOKED TURKEY, cut into 3/4-inch dice
Melt butter in a large heavy Dutch oven or saucepan over medium heat. Sauté onions over medium-high heat until translucent. Add sliced mushrooms and sauté 5 more minutes. Add stock to kettle and bring to a boil.
Blend flour with water to form a smooth mixture and whisk into saucepan. Reduce heat and simmer 5 minutes, stirring, until thick and smooth.
Stir in poultry base and white pepper. Continue to cook and stir until thick and smooth, about another 5 minutes.
Reduce heat to low. Stir in milk, sour cream, parsley and turkey. Heat gently, but do not boil, for 5 minutes.