Original Korean: 오랜만에 보는 커피는 맥심 선생님. (어린 ver )
오랜만에 - Been a long time since
"오랜만" means a state in which a long time has passed since something happened, with the position particle at the end.
보는 - see (descriptive)
"보" is the stem of the verb for to see ("보다") with the descriptive modifier at the end, turning into a descriptive verb.
커피는 - coffee (topic)
"커피" is the noun for coffee with the topic particle on the end.
맥심 - Maxim
This is the English word "Maxim" written in Korean, which is among other things an instant coffee brand.
선생님 - teacher/master
"선생님" means a teacher or master.
(어린 ver) - (young ver.)
"어린" means young.
I chose the idiom "Long time no see" as a replacement for "Been a long time since we've seen".
Long time no see Maxim Coffee Teacher. (young ver.)