1. Heat large nonstick skillet on medium heat. Add mustard seed; cook and stir 1 minute or until fragrant. Immediately pour out of hot pan to avoid over-toasting. Coarsely crush seeds using a rolling pin or a mortar and pestle. Pour into shallow dish. Stir in flour, sea salt and pepper. Coat chicken on both sides with flour mixture. Reserve 1 tablespoon of the remaining flour mixture.

2. Melt butter in same skillet on medium heat. Add chicken; cook 5 minutes per side or until golden brown. Remove chicken. Keep warm. Add shallots and garlic; cook and stir 2 minutes or until softened. Add vermouth, stirring to loosen browned bits in bottom of pan. Stir reserved flour mixture into broth with wire whisk until smooth. Stir into skillet. Bring to boil. Return chicken to skillet. Reduce heat to low; cook 5 minutes or until chicken is cooked through and sauce is slightly thickened. Add tomatoes; cook and stir until heated through.

3. Serve chicken with steamed green beans and cooked rice, if desired.