Final answer:
The phrase 'as a dressing' in the provided sentence is a prepositional phrase, which begins with a preposition and provides additional details about how something is used.
Step-by-step explanation:
The phrase in parentheses in the sentence 'Doctors in India report using potato skins as a dressing to heal burn victims' is a prepositional phrase. A prepositional phrase generally begins with a preposition and functions as an adjective or adverb to provide additional information about time, location, or direction. In this sentence, 'as a dressing' begins with the preposition 'as' and serves to explain the manner in which the potato skins are used, which is typical of a prepositional phrase.