Amazing! Four pages of recipes and not one of them right! Now, listen up...
Start off with the right spuds: King Edwards ideally, Maris Piper at a pinch.
Choose ones that are all the same size and can be halved for the perfect final size, and/or enough bigger to be cut in 3 or 4 to get the same final cut size.
Put them in your big lidded pan, add a level tsp or so of salt, add boiling water till just covered, then return the boil and simmer for about five minutes, testing with a fork to see when you can feel just a bit of 'give'. If they still feel completely hard, keep cooking.
When they feel just a bit softened, use the lid to help drain all the water off down the sink. Put the pan back on the hob (no heat) for a few seconds. Add a fair bit of (good) salt. Put the lid back on. Grab the pan top and bottom, using oven gloves, and give it a good shake. Remove lid to check for 'chuffing' (a word I'd never heard, but I like it!) You may have to shake a bit more, depending on how cooked the spuds were. If there's mashed spud everywhere, you probably over-cooked. Don't shake any more, and remember for next time...(they'll still be fine - don't worry)
Upend onto a bowl/plate, another good sprinkle of salt, and leave to cool down for a few minutes, then into the fridge (uncovered) for an hour. (Not essential, but it helps them dry more, then take up more oil for max crispiness.)
Olive oil (healthy) in baking tray on the hob...heat it up a little to help thin. Spread over full surface. Add spuds and use a fish slice to turn them about until all are oiled all over. (Add a little more oil if necessary.) Add another sprinkle of salt.
Top of 190 degree oven for 50ish mins. Use the fish slice to turn them over a couple of times during the cook.
If they don't turn out perfect, blame someone else.