A man who is able to move his penis in a circular motion while inside a woman's vagina. It is only possible to "stir the stew" if the woman has been with far to many men, which leads to extreme stretching of the vaginal canal.
Bob: I think i'm gonna ask Alissa out.
Henry: She has been with everyone! including Jeron..
Bob: I saw Jeron's dick in the locker room on friday. It looks like a black baby's leg..
Henry: Yeah, you're gonna stir the stew fo sho!