4 Tbls. vegetable oil
1 medium onion, 1 stalk celery, 1 carrot, sliced
2 small chicken breasts
1 oz. dried Matsutake mushroomsrehydrated
6 Tbls all purpose flour
2 1/4 cups chicken broth, boiling
2 Tbls sherry
2 tsp. mustard
2 tsp. wine vinegar

Heat oil in large pan, add onion, celery, and carrot and saute. Cut chicken into bite size pieces. Add chicken and mushrooms to vegetables, cook briefly, then add flour. Remove pan from heat and stir in broth gradually so that the flour is completely absorbed. Return pan to heat and simmer gently to thicken, stirring. Add mustard, sherry and vinegar and simmer 20 more minutes. Season to taste.