As above re olive oil.
Personally I like to heat a jug of oil in a microwave for 2-3 minutes (not enough to boil it, but get it hot), then either poour this over the piece, or just sit the spoon in the oil until it stops fizzing.
A downside of this is that if you use hot oil for too long, or get it too hot, it can slightly 'toast' the wood, darkening it. Not a problem if you don't mind that. I generally only do this for a spoon that I intend to see regular actual use, as the hot oil seals the wood very effectively.
Walnut oil and groundnut oil are my favourites, or rapeseed oil if I need to avoid nut allergies.