Beautiful enough for special spring dinners, yet easy enough for weekday suppers, these chicken breasts are bursting with the fresh flavors of simple ingredients. This recipe can also be doubled if you have extra guests. Remove one-quarter of each sweet pepper; cut out a few decorative shapes and set aside for garnishing. Cut remaining sweet peppers into thin strips. In nonstick sksillet, melt butter over medium heat; cook sweet pepper strips and 1/4 tsp each of the salt, pepper and thyme, stirring, for 3 minutes. Set aside. Pat chicken breasts dry. Place, skin side up, between 2 sheets of waxed paper; pound lightlyu to 1/4-inch thickness. Turn chicken over; sprinkle skinless sides with 1/4 tsp each of the salt and pepper. Place sweet pepper strips crosswise on short end of each chicken breast; roll up and secure with toothpicks. Sprinkle with remaining salt, pepper and thyme. In same skillet, brown chicken lightly on all sodes. Transfer to baking sheet; bake in 375F 190 °C oven ;for 10-15 ;minutes or until chicken is no longer pink inside. Meanwhile, in skillet, bring chicken stock to boil, stirring to scrape up any ;brown bits. Stir in Dijon mustard; cook, stirring, over medium heat for about 2 minutes or until slightly reduced. Spoon over chicken. Garnish with sweet pepper cutouts.