It is a roll where one wing is stalled. The lift imbalance causes rapid rotation. Some aircraft are designed with airfoils and control surfaces which encourage this.

You would do this at mid to high speed by raising the nose then applying opposite ruddder to the aileron input. Some models will do this easily others will not do it at all. It helps to have a rearward CofG.

WARNING THIS IS A VIOLENT MANOUVRE AND CAN BREAK MODELS.