I used to hear that when you finished eating ramen and you should say this as a replacement speech of "thank you". It basically means "It must be tired of you to go around to design and prepare for the meal" which implicitly implied an appreciation

Talking about being "tired", the phrase お疲れ様でした (otsukaresama deshita) is commonly used to express "thanks for the hard work" and it's a catch-all greeting for coworkers now, but it literally means something like "o tired one" and the character 疲 still means tired.

You can look it up, it's in online dictionaries.

gochisou: "feast"

sama: honorific

deshita: past conjugation of "desu", meaning "is"; thus, "was"

In other words, "[that] was a feast".