Chili's Grill and Bar Chicken Mushroom Soup

Source: Milwaukee Journal Sentinel, January 9, 1999

1/4 cup (1/2 stick) margarine
1/4 cup diced yellow onion, cut into 1/4-inch pieces
1/4 cup diced carrots, cut into 1/4-inch pieces
1/4 cup diced celery, cut into 1/4-inch pieces
3 cups sliced mushrooms (about one
    8 ounce package), cut into 1/8-inch slices
1/2 cup all-purpose flour
5 1/2 cups chicken broth
Pinch of dried tarragon
1/4 teaspoon dried thyme
1/2 teaspoon white pepper
1 teaspoon black pepper
1/2 teaspoon hot pepper sauce
1 tablespoon chopped fresh parsley
3 cups half-and-half
1 1/2 teaspoons lemon juice
3/4 pound diced cooked chicken

Melt margarine in large heavy pot. Add vegetables and saut