To this you can add any spice or flavoring you choose. You can add a few tablespoons of grated Parmesan cheese for a nice variation. The point to remember is with most recipes, they are suggestions on how to prepare the foods. They are not hard scientific formulae. Two flavorings to master for the barbecue are garlic and onion.
Onions are a snap on the grill.
Peel and slice the onion into thick slices. Brush the slices with olive oil and grill over high heat for 3 or 4 minutes per side. Serve them with your burgers of steaks. With garlic, I think the technique popularized by Chef George Hirsch on public television is the best one for the grill. Brush the head with olive oil and place on the cooler outer part of your grill for 20 to 30 minutes.