Was Buddha/did Buddha teach Vegetarianism?

**On the matter of Vegetarianism** I am aware the Theravada canon states that Buddha allowed monks to consume meat on the basis that they did not see, hear, know or suspect have been slaughtered for them. However Mahayana Sutras state that the Buddha forbade eating meat for example in the lankavatara and Surangama sutras. Which position would be more authentic, and how do we know whether the Buddha taught Vegetarianism or not?