1. salt and pepper chicken, brown in lge pan, in butter until fully cooked, about 10 mins/side.
2. remove from pan and keep warm.
3. add onion and thyme, cook until softened.
4. add vinegar and wine, bring to a boil.
5. add stock and tomato paste, reeduce by half.
6. add cream, add mustard.
7. spoon sauce over chicken, garnish w/parsley.