Chicken In Champagne And Mushroom Sauce

1 chicken, about 4 lb, cut into 12 serving pieces
1 shallot, minced
12 tarragon leaves
Salt and Freshly ground pepper
2/3 cup brut Champagne
1/2 cup light cream
1/2 teaspoon arrowroot
1 teaspoon mustard
1 lb very fresh mushrooms

Remove the skin from the chicken pieces and make incisions in the flesh. Put the chicken, shallot and tarragon into a 10 1/4 inch nonstick saut� pan. Season with salt and pepper and add the Champagne. Bring to a boil over low heat. Stir, cover and cook for 30 minutes.

Meanwhile, mix the cream, arrowroot and mustard. After the chicken has cooked for 30 minutes, pour this mixture into the pan and cook, covered, for another 15 minutes over low heat.

Meanwhile, cut off the mushroom stems level with the caps and discard them. Wash the caps, pat dry and finely slice.

Add to the pan after 45 minutes' cooking time and cook, uncovered, for 10 minutes, stirring often.

Serve immediately.