"Beth gest ti i frecwast?"
Translation:What did you have for breakfast?
Yes, "beth" means "what" and it is derived from "peth" which means "thing" (peth + SM = beth)
'What have you got' is the present tense and without 'got' would be 'what do you have'
The version of 'got' for the past tense would be 'What did you get'