Where can I break down mutagens?
In Witcher 3 you need several "generic" mutagens in order to craft a greater mutagen, and I think I saw somewhere that you can dismantle them. For example, take a griffin mutagen and get a generic lesser green one. Or was I mistaken?
You cannot break down Mutagens - you have to find them on monsters, and craft them through Lesser -> Regular -> Greater.
There is only one place you can do this At the table at the hidden laboratory in the cave under the estate at corvo bianco