You need to wait three minutes after you put the hot water in your cup of noodles until they are ready.
It takes three minutes until your noodles are ready after you pour the hot water in.
ーYou need to wait three minutes after you put the hot water in your cup of noodles until they are ready.
「カップラーメンにお湯を入れた後、食べられるまでに3分待つ必要がある」
to wait three minutes で「3分待つ」
to put the hot water で「お湯を入れる」
ーIt takes three minutes until your noodles are ready after you pour the hot water in.
「お湯を入れた後、ラーメンができるまでに3分かかる」
It takes ○ minutes で「○分かかる」
to pour the hot water in で「お湯を注ぐ」
ご参考まで!