Have you already check at brewing pot? Maybe you have learn it already.
By the way, you can brew restrain potion even you don't have received a recipe by brew it yourself. Once you have been brew something. The recipe will be add to your recipe list.
At the brewing, there 5 slots to fill ingredients. The recipe of restrain potions is..
First slot: Leave it blank
Second slot: Berry (Red)
Third slot: Nut
Forth slot: Leave it blank
Fifth slot: Nut
