Be (as) easy as one-two-three American British informal
To be extremely simple, basic, or intuitive without much skill or effort
I have worked for a famous restaurant as a chef, so cooking for a small party is as easy as one-two-three.
Making rainbow popsicles was as easy as one-two-three!
For Lisa, taking an English test is as easy as one-two-three.
Something easy or pleasant to do, especially by comparison to something
A legal matter that is very easy to solve
One needs to understand the basic techniques or primary details of something before taking actions that require greater skills
Especially easy
A simple, quick or evasive answer
The verb "be" should be conjugated according to its tense.