Savor the flavors of a classic ratatouille sandwich on crispy sourdough, with layers of roasted and softened vegetables and melted mozzarella. To create this delight, roast a colorful medley of veggies until tender and fragrant, about 25 minutes, then assemble with mozzarella and toast for a comforting sandwich. Enjoy it as a panini or in a sandwich press for a delightful, melty finish.