- Preheat barbecue to medium-high heat.
- Gently scrub mussels with a brush in cold water and remove beards (small threads). Combine butter, flour, white wine, chicken broth, garlic, cream and Parmesan in blender until smooth and well blended. Reserve.
- Stack two large sheets of aluminum foil, one on top of the other, on work surface. Place one-quarter of the mussels in the middle. Cover with two more sheets of aluminum foil and tightly fold over three sides to form a pouch. Pour one-quarter of the sauce into the pouch. Fold over remaining side tightly. Repeat operation three more times to make four pouches in all.
- Place pouches on barbecue rack, and cook for 10 to 12 minutes, or until mussels open (discard any that stay shut). Turn over and shake pouches several times during cooking. Serve mussels and sauce in four large bowls. Garnish with fresh parsley and freshly ground pepper. Accompany with olive or rosemary bread and a green salad.
: For rosé sauce, add 60 mL (1/4 cup) tomato sauce to the mixture and garnish with fresh basil.