8 skinless boneless chicken breasts
1/4 cup (50 mL) Dijon mustard
16 thin slices prosciutto, (about 8 oz/250 g)
2 tbsp (25 mL) butter, melted
1/2 tsp (2 mL) each salt and pepper
1 cup (250 mL) chicken stock
1/2 cup (125 mL) white wine,(or chicken stock with 2 tsp/10mL white wine vinegar)
2 tbsp (25 mL) all-purpose flour
2 tbsp (25 mL) minced fresh parsley
Place each chicken breast, smooth side down, between plastic wrap; with flat side of meat mallet, pound to a generous 1/4-inch (5 mm) thickness. Brush top with mustard. Place 2 slices prosciutto over each; beginning at narrow end, roll up and secure with toothpick. Place, seam side down, in small roasting pan. (Make-ahead: Cover and refrigerate for up to 24 hours.)
Brush rolls with butter, sprinkle with salt and pepper. Pour in stock and wine. Roast in 425∞F (220∞C) oven until chicken is no longer pink in centre, about 15 minutes. Baste with pan juices, broil until golden, about 4 minutes.
Transfer chicken to cutting board, cover and keep warm. In small bowl, whisk flour with 2 tbsp (25 mL) water; whisk into pan juices and bring to boil. Reduce heat and simmer, whisking, until thickened, about 4 minutes. Stir in parsley. Serve with chicken.