A Muslim-owned restaurant sells haraam meat.

Answer

If the owner of the restaurant which sells haraam meat is a Muslim, then it is not permissible to buy anything from such a faasiq who so flagrantly dishonours the Shariah. A faasiq should never be trusted. If the owner is a non-Muslim, and one has certitude that the bread is not contaminated with haraam, then it will be permissible to buy the bread and other halaal items. Nowadays big supermarkets and hypermarkets have bakeries and butcheries on their premises. There is total separation between the bakery and the butchery. If the ingredients in the bread are all halaal, then the bread may be bought from such a store.