HEAT oven to 350ºF.
PLACE chicken on rimmed baking sheet sprayed with cooking spray; spread with mustard. Mix nuts and thyme; sprinkle over chicken.
TOSS Brussels sprouts with dressing; add to baking sheet with chicken.
BAKE 30 to 35 min. or until chicken is done (165°F).
TOSS Brussels sprouts with bacon; serve with chicken.