Cut fish into serving-size pieces. Place milk in a shallow bowl. In another shallow bowl, combine potato chips, Parmesan cheese and thyme. Dip fish in milk, then coat with the potato chip mixture. Sprinkle a greased 8" square baking dish with bread crumbs. Place fish over crumbs; drizzle with butter. Bake, uncovered at 500 for 12-14 minutes or until fish flakes easily with a fork.