Can't live without: gochujang
If your Korean is as bad as mine – and mine is non-existent – being able to track down the Korean chilli paste gochujang could seem like a tricky task. It's not hard to find places that stock it, as every Asian grocery I've ever been into carries it, but you are not going to find it with a big label in English. Fortunately – and I have no idea why this is true – every brand of gochujang comes in a bright red plastic tub like the one above. You can spot it a mile away.
When you find the red container, there will usually be a photo of chillies on it somewhere, so naturally you might conclude that it's some kind of super-concentrated five-alarm ingredient, but it's not at all. The chillies in gochujang are fermented with soy beans and rice, and what's surprising is that it's sweet rather than hot. It has the same consistency and concentration of flavour of tomato paste but, unlike tomato paste, has a very long shelf life once opened, as long as you store it in your fridge.
It's a staple on Korean kitchens and has become a staple in mine. I'm always experimenting with new ways to use it, especially in marinades and for kicking stews up a notch. For two examples here, try my version of the Korean classic daeji bulgogi or the delicious marinade for firecracker chicken.