This phrase from French is a shortened form of à la mode de ("in the style of"). In English, à la is used, frequently overused, to mean "in the manner of," "like," "according to." Its appearance in a sentence such as "She dresses à la a Hollywood star" is correct but also pretentious and forced. Restrict use of à la to such standard expressions as "a la carte" and "à la mode," for which there are no acceptable substitutes in English.
Dictionary of problem words and expressions. Harry Shaw. 1975.