PREHEAT oven to 450˚F or grill to medium-high.
TEAR off four, 12x18 inch sheets of ALCAN® Ultimate Grilling Foil.
FOR each packet, place one halved chicken breast in centre of each foil sheet with the non-stick (dull) side toward food and arrange broccoli around it. Spread 1 teaspoon garlic over each chicken breast, then top with 1 tablespoon of Parmesan cheese, ½ tablespoon of capers (optional) and top with two lemon slices. Add one tablespoon of butter on top of lemon slices.
BRING up foil sides. Double fold top and ends to seal packet, leaving room for heat circulation inside. Repeat to make 4 packets.
PLACE packets onto rimmed baking sheet.
BAKE 18-22 minutes in the oven or grill 12-14 minutes in covered grill.
REMOVE pan from oven or use tongs to slide hot packets from grill onto pan or plate. Open packets carefully by cutting along top folds with a sharp knife, allowing steam to escape. Then open top of foil.
GARNISH with freshly chopped parsley before serving (optional).