For the best flavor, use freshly grated Parmesan cheese from a block. A microplane works well for grating, while a vegetable peeler creates elegant shavings. The garlic oil can be made ahead of time and stored in the refrigerator for up to 3 days. Be sure to bring it to room temperature before brushing on the baguette slices. If you don't have a rotisserie chicken, you can use leftover grilled or baked chicken breast. Toasts can stand uncovered for up to 2 hours.