Heat gas or charcoal grill. Cut 4 (18x12-inch) sheets of heavy-duty foil. Place each ear of corn on centre of 1 foil sheet. In small bowl, mix herb butter ingredients. Brush or spoon herb butter over surface of each ear. Bring up 2 sides of foil so edges meet. Seal edges, making tight 1/2-inch fold; fold again, allowing space for heat circulation and expansion.