in a medium bowl, mix 2 tbs of vinegar, mustard and garlic. add chicken. turn to coat
3
transfer chicken and marinade to skillet. saute chicken until cooked through about 3 min on each side. transfer chicken to platter and keep warm
4
heat remaining tsp oil in skillet. saute mushrooms for 1 minute. add broth, thyme and remaining vinegar. cook stirring occasionally until mushrooms are a deep brown, about 2 minutes longer.