COOK and stir bacon in small saucepan on medium heat until crisp. Remove bacon from pan with slotted spoon; drain on paper towels. Add onions, thyme and bay leaf to drippings in pan; cook 3 to 4 min. or until onions are crisp-tender, stirring frequently. Add garlic; cook 1 min. Add wine and steak sauce, cook and stir 4 to 6 min. or until slightly thickened. Stir in bacon. Remove from heat; cover to keep warm.
HEAT oil in small skillet on medium-high heat. Add chicken; cook 6 to 7 min. on each side or until done (165ºF).
REMOVE and discard bay leaf from sauce. Spoon sauce over chicken.