1 Leia: Han, a medal for you.
2 Leia: And Luke, a medal for you.
3 Chewbacca: Grwha gr roawrr?
3 Leia: I thought your species didn’t approve of physical rewards.
4 Chewbacca: Raaorgh gffh graah?!
4 Han: <snicker>

Originally, brain mangled by too much Darths & Droids writing, I simply wrote Chewbacca's dialogue in English.

Then when assembling the comic I looked at it and thought he really shouldn't be speaking English. I should use the incomprehensible grunts and growls that he uses in the movies. And then I lamented that I couldn't change it from English, because then nobody would understand the dialogue and the joke would be ruined.

But then I realised that you don't actually need to see explicitly what Chewbacca is saying at all, and the joke still works just fine. It's pretty easy to imagine from context what Chewbacca is saying.