To make this recipe gluten free, replace the French bread with a sturdy certified gluten-free baguette or loaf that can hold the toppings well. Also confirm that the Worcestershire sauce, mayonnaise, provolone cheese, and any packaged ingredients are labeled gluten free or free from cross-contact concerns, as some brands may contain hidden gluten. If preparing in a shared kitchen, use clean pans, utensils, and prep surfaces to help prevent gluten contamination.