For example, Marmite Crumpets don't exist. You cannot buy them at the supermarket. To be clear: you can buy crumpets, you can buy marmite, you can buy butter; but you have to assemble them at home.
If you walk into a breakfast cafe, they will happily serve you sausage / egg / bacon / french toast / bubble / squeak (whatever that is). But no marmite crumpets. If you ask them to make it, they will give you a very strange look. It's not typically offered. It's something you just have to make at home.
It is unbuyable. Any tourist who comes to the UK to try a Marmite crumpet would need to bring a toaster or an oven with them, or quickly befriend a brit and hope that they have all the ingredients at home.
It's not a secret. You just can't have it.
*munches into crumpet thoughtfully, and salivates at the juicy savory delight, whilst staring at you pityingly and condescendingly*
Anyway, what's something that I could never experience unless I made it myself in your local?
Food that is actually spicy. I know it is available at some locations on earth, but I do not live within 500 miles of any of them. The only place near me that even offers a legit hot sauce is a food truck and that one is still a bit tame.
Iโve never seen sourdough French toast at a restaurant and it is literally the best bread to use. The texture holds up well to the egg dunk and the funky sourness complements the otherwise cloyingly sweet dish. Even better, instead of syrup I use salted irish butter, making it a savory dish with a hint of sweet cinnamon.