Cook pasta according to package directions, omitting salt and fat; drain.
While pasta cooks, cut chiles in half lengthwise; discard seeds and membranes. Place chile halves, skin sides up, on a foil-lined baking sheet; flatten with hand. Broil 6 minutes or until blackened. Place in a paper bag; fold to close tightly. Let stand 5 minutes. Peel and cut into bite-sized pieces.
Combine breadcrumbs, oil, rind, and red pepper in a bowl. Place 3/4 cup milk, stock, flour, and garlic in a saucepan, stirring with a whisk. Bring to a boil; cook 3 minutes or until thick, stirring frequently. Remove from heat. Stir in chiles, 1/4 cup milk, cheese, and next 4 ingredients until smooth. Stir in pasta. Spoon mixture into an 8-inch square broiler-safe glass or ceramic baking dish coated with cooking spray. Top with breadcrumb mixture. Broil 1 minute or until browned.