tablespoon fresh basil (I always have loose frozen fresh basil and frozen basil cubes)
teaspoon sriracha chili sauce (start with 1 and add more to taste)
Preheat gas BBQ to low heat. You can just use one part of your grill for this and cook meat, etc. on the other part.
Mix together the mayo, parmesan cheese, garlic cloves, basil and chili sauce. Spread the mixture over each half of the loaf.
Set the bread halves on the grill, cut side up, over low heat. You want the topping to heat up and the bottom to brown up a bit and crisp. It takes about 10 - 15 minutes. If you want to, you can place the bread on a top rack while you cook everything else. Just make sure it doesn't dry out.