I usually use olive oil or butter but I usually have a small bottle of cold pressed rapeseed oil from hill farm. I don't use much oil so a small bottle is handy. They have been producing for 20 years and are well regarded. You used to only get it in farmshops but it is readily available now.
hillfarm | the original producers of cold pressed rapeseed oil
The first farm in the UK to grow, press and bottle their own cold-press rapeseed oil. Versatile in the kitchen with many nutritional benefits.
hillfarmoils.com