It's possible you're thinking of "sahha" which is a common Arabic word used in Algeria and across the Arab world.
Sahha means:
* "Health" in the sense of wishing someone good health.
* "Cheers" when toasting with a drink.
It's likely that "sahtek" is a phonetic misspelling of "sahha."
If you're looking for a word in Algerian Berber, you might want to double-check the spelling or provide more context.