Cheapest way to boil a pint of water?????

i do thermos too, and if i boiling veg, i always boil water in kettle first, then pur over veg on hob.

but would be cheaper to boil in pan for this
because veg etc would start cooking while water is heating up

sorry, i should have clarified, i never do root veg (well rarely) on stove top, i tend to oven cook, so what i do boil on top is brocoli, spinach, cauli etc, which is better in hot as math says.

but yes, root veg prob better off in cold water.

Keep the kettle descaled: the water will boil quicker. And only boil what you need rather than a full kettle each time. And if your hot water comes from a combi boiler rather than a hot water tank you could let the tap water run hot then fill the kettle. But that might get more expensive if your water is metered, especially if your boiler is a long way from the kitchen.