Bring rice, 4 cups chicken broth, and 1 seasoning packet from rice mix to a boil in a saucepan over medium-high heat. Cover, reduce heat to low, and simmer 20 minutes or until liquid is absorbed and rice is tender. (Reserve remaining seasoning packet for another use.)
Meanwhile, melt 3 Tbsp. butter in a large skillet over medium heat; add mushrooms, onion, and celery, and cook, stirring often, 10 to 12 minutes or until tender.
Melt 1/4 cup butter in a Dutch oven over medium heat; whisk in flour, and cook, whisking constantly, 1 minute, or until thickened and bubbly. Gradually whisk in remaining 6 cups broth, and cook, stirring often, 8 to 10 minutes or until slightly thickened. Whisk in half-and-half and wine. Stir in mushroom mixture, chicken, and rice. Cook, stirring occasionally, 5 to 10 minutes or until thoroughly heated. (Do not boil.) Garnish, if desired.
Fabulous soup!!! We had it with sour dough bread. Might be good as a first course for company also. I made half a recipe which worked fine in which case I divided the broth as 2 cups with the rice and 3 cups later on. I did however use "all" 2 T. of wine! :) :)
The only problem I found was it seems that the recipe was off in it's measure for the roux. When followed as printed, the roux was far too dry. Either double the butter or reduce the flour by half for a successful roux.
We have soup for lunch just about every day when the weather is cold, and this goes into the top two or three in my soup recipe collection. A real winner, as good as it gets. Very flavorful and reheats well.