Here are a few possibilities:
German Origin:
* "Boo-keh" is the most common pronunciation for German speakers. The "ue" is pronounced like the "oo" in "moon."
French Origin:
* "Bwesh" is a possibility if the name is of French origin. The "ue" is pronounced like the "ew" in "few."
Other Possibilities:
* "Bee-chee" could also be a pronunciation if the name is anglicized.
To be sure, the best way to find out how to pronounce "Bueche" is to ask the person who has the name.