Get it right and panna cotta might be one of the dreamiest desserts on the planet; get it wrong, and it could double as a weapon. My first attempt at panna cotta was a disaster; hard and rubbery, slightly grainy, and not particularly palatable. In truth, if I’d thrown one at a wall, it would have bounced right back at me. With no alternative, I served it up apologetically to dinner guests and the meal ended on a lacklustre note…..