The Vaṇijjāsutta:
Pañcimā, bhikkhave, vaṇijjā upāsakena akaraṇīyā. Katamā pañca? Satthavaṇijjā, sattavaṇijjā, maṃsavaṇijjā, majjavaṇijjā, visavaṇijjā — imā kho, bhikkhave, pañca vaṇijjā upāsakena akaraṇīyā”ti.
Sattamaṃ
There are many translations regarding above quoted text, not sure which one needs to be included. But from what I understand, if one raises a pig and kill it in order to sell its meat, this is considered wrong livelihood.
But what if the restaurant owner simply buys meats and cook them and then sell them, is this considered wrong livelihood?