I don't bother preheating the oven.
If it says 180oC for 30 mins, the food goes in and oven switched on at same time. 30 mins later and the food is ready the same as if I preheated for 5-10 mins and cooked for the 30 mins.
Waste of time and energy preheating.
I hope I never get served food by you!
![Cry laughing :cry: :cry:](/styles/default/xenforo/vbSmilies/Normal/cry.gif)