A colleague of mine was working in a police station in N Wales. He had brought a Fray Bentos steak and kidney pie in a tin for his lunch.
He put the oven on, and once at the correct temp he put the can in the oven. He neglected to open the can and remove the lid.
About 30 mins later there was an enormous bang and people rushed to the kitchen area. The oven door had been blown off the cooker by the force of the steel can exploding and the canteen area was covered in superheated steak and kidney.
How we laughed when he had to explain what he had done…