Can anyone solve this riddle?

[Goats]

my friend's boyfriend is moving away soon to see his family and before he goes, he is surprising her with something. The clues he has given so far are:
- You could put it in a stew but it wouldn't taste good
- You can have many of these but each one would be unique
- It has to be a surprise because it means a lot
- The future starts after the surprise

What could it be?!?!
they've been dating a few years so it's likely, but 'You can have many of these but each one would be unique' !?!?!

 

[RebaW]

I would guess diamonds (as would go in an engagement ring)

 

[john]

Something to do with pearls.

 

[al]

How long have they been dating -- It could insinuate a engagement ring or a ring.