magic bullet
From Longman Dictionary of Contemporary Englishmagic bulletˌmagic ˈbullet noun [countable] 1 a drug or treatment that can cure a disease or illness quickly and easily2 SOLVE/DEAL WITH A PROBLEM informal something that solves a difficult problem in an easy way There’s no magic bullet for school reform.Examples from the Corpusmagic bullet• For the general population, beta carotene is not a magic bullet.• A magic bullet for inflation, claim some writers.• But there is no magic bullet.