Wa alaykum salam wa rahmatuLlahi wa barakatuHu,
Animals must be slaughtered according to Islamic ritual for their meat to be permissible. It is not permissible to consume non-halal meat from such restaurants. Reciting the “basmalah” over carrion does not make it permissible.
And Allah knows best.
Answered by Shaykh Yaqub Abdurrahman