expression
totally different; completely; on a whole other level
Emphasizes that something is markedly different or superior, often used with 違う or 上.
彼の料理は一味も二味も違う。
His cooking is on a whole other level.
この新製品は一味も二味も上だ。
This new product is completely superior.
一味違う means 'a bit different' or 'having a unique touch', while 一味も二味も違う intensifies the difference to 'totally different' or 'on another level'.
From 一味 (ひとあじ, 'one flavor') + も + 二味 (ふたあじ, 'two flavors') + も, literally 'both one flavor and two flavors', used to emphasize a large difference.