I built small pen outside main base and outside moat. It has narrow path to bridge with a piece missing. When I came across 1 star a good ways from base. I simply ran to this pen, stopping now and then to make sure boar was in pursuit and still aggroed. Then have boar chase you inside pen and walk out, closing gate. Leave food. Takes about 2 days. I also stayed nearby to make sure nothing attacked him cause this pen is outside my moat. Wasn't babysitting. Just picking berries or cutting wood not too far away to check on him now and again.

Once tamed, I close missing part in bridge and push him through pathway that I narrow so he can't turn around. Then they go into pen/pit with other boars. Still have outside of moat 'training' pen for when I find a 2 star. I went to all pits for permanent boar farm after reading someones tip.