Preheat grill to 400°F (200°C). Melt 1/4 cup (60 mL) butter; mix with garlic, basil, oregano and 1/4 tsp (1 mL) salt. Set aside.
In large bowl, mix together flour, baking powder, sugar and remaining 1/2 tsp (2 mL) salt. Cube remaining 1/2 cup (125 mL) butter; cut into flour mixture with pastry-blender or rub in with fingertips until mixture resembles coarse meal. Stirring with fork, gradually add just enough milk to moisten mixture (do not overwork). Gently shape 1 tbsp (15 mL) amounts of dough into balls, using up all the dough.
Brush oil in bottom of 10-in. (25-cm) cast-iron skillet. Arrange half the dough balls in single layer in skillet. Brush with reserved butter mixture. Arrange remaining balls in second layer over top; brush with remaining butter mixture. Sprinkle with Parmesan cheese.
Place on grill over indirect heat. Close barbecue lid; cook 20 min. or until surface of bannock is firm and edges are golden. Serve warm or at room temperature.
Make this in 375°F (190°C) oven by covering skillet with foil and baking 15 min., then uncovering to bake an additional 20 min.