Cheese-Stuffed Chicken Breasts with Creamy Chive Sauce

Ingredients

• • 20 small baby potatoes, about 1 1/2 lb (675 g)
  • 1 tbsp (15 ml) olive oil
  • 12 Brussels sprouts, trimmed and halved
  • 1 onion, thinly sliced
  • 4 boneless, skinless chicken breasts
  • 2 tbsp butter
  • 6 green onions, thinly sliced
  • 2 garlic cloves, chopped
  • 1 shallot, thinly sliced
  • 3 1/2 oz (100 g) Gruyère cheese, cut into 4 slices
  • 8 slices prosciutto
  • 1 container (220 g) creamy shallot and chive sauce (Boursin-style)
  • 1/4 cup (60 ml) chicken broth
  • 3 tbsp flat-leaf parsley leaves