Heat management

How a pan is heated, held and allowed to cool: preheating slowly and evenly, matching the burner to the pan's size, and never cooling in water. This is what keeps a base flat and a seasoning intact.

Preheat an empty skillet 6 to 8 minutes on a medium setting rather than 3 minutes on high. A 12 in pan heated fast bows in the centre and then spins on a flat hob.

A high burner does not heat a thick pan faster, it just heats it unevenly. The centre comes up first, and the difference between centre and edge is what warps a base.