I think we’ve done this kind of thread before, but I love learning other peoples’ kitchen tricks!
I just made an apple crumble, and I added a few big handfuls of sesame seeds to the topping. Delish! I buy them in a big jar from the Asian supermarket.
Anchovy paste in sauces and stews. Most savoury things can benefit from the salty umami boost. It doesn’t end up tasting fishy, if you just use a little. Also works with little fillets, they usually disintegrate if you add them with the sauteeing onions.
Golden syrup - I use this in place of corn syrup or honey in various caramel applications. So yum. Also great in oatmeal/porridge with currants.