「不二法門」

(pos:名詞)
<explanation>
yue:要達成某目標嘅唯一一個正確途徑，最好或獨一無二嘅方法
eng:the only correct approach to a subject, the best or the only way
<eg>
yue:要屋企冇曱甴，保持室內整潔係不二法門。 (jiu3 uk1 kei2 mou5 gaat6 zaat2, bou2 ci4 sat1 noi6 zing2 git3 hai6 bat1 ji6 faat3 mun4.)
eng:If you don't want cockroaches at home, keeping your place tidy and clean is the best method.