Double, Double, Toil, and Trouble

Double, Double, Toil, and Trouble is an achievement/trophy in the first Bayonetta that is unlocked by making 20 Concotions.

Description
"Create 20 Concoctions"

Guide
You will come across ingredients: Baked Gecko for defense, Mandragora Root for vitality, and Unicorn Horn for the offense. You use these in recipes to make different kinds of useful items.

In order to concoct something goes to the Item Menu and looks for the recipes. Add ingredients then mix them.