To make this Chicken Milanese with Roasted Pepper and Tomato Sauce gluten free, replace the all-purpose flour with a gluten-free 1:1 flour blend or gluten-free rice flour, and use certified gluten-free panko or gluten-free breadcrumbs. Also check that the Dijon mustard, canned tomatoes, roasted red peppers, red wine vinegar, and any packaged ingredients are labeled gluten free, since brands can vary or be processed in shared facilities. For anyone with celiac disease or severe gluten sensitivity, use clean pans, utensils, racks, and serving dishes to avoid cross-contact.