I don’t live in the UK, so can’t tell you where or if this is available, but do you like tinned fish? 10 years ago you couldn’t have paid me to try sardines or anchovies or smoked oysters (or mussels), but now I keep a stash on the shelf for when I want a bit of something savory. Particularly the smoked oysters appeal to me. I only know of one brand, in the US, that is available with olive oil (Crown Prince) but that is an important thing to look for IMO. I always read the labels because I believe they have some with canola or soy as well.
The quickest dip in the world: equal amounts of mayonnaise & sour cream, + your favorite herbs, fresh if you have them, otherwise dried. Dill or chives are particularly nice. Dress it up with some finely chopped bell pepper if you want, but it isn’t necessary..