Find a pink tree leaf (dropped by Araf Kul, the boss of the Orc camp) and an apple (sold at LH).
Bring them to Dunikus Cathbad, at the druid camp, and say potions, yes, then potions again.
Dunikus will not make a second potion immediately after the first one; you will need to wait 30 minutes before requesting the second.
Reward:
You can complete this quest as many times as you wish.