The most successful stocking stuffers are a perfect mix of mundane and special, and bonus points if it’s something the owner of the stocking would never buy for themselves. This is what makes spices — really good spices — the perfect stocking stuffer for anyone who cooks (or wants to learn to cook).
I’m not talking about blends, though I have recs for those too. Blends are not as versatile as a single spice, and they don’t encourage as much curiosity in the kitchen. I’m talking luxe versions of universally useful pods, seeds, and powders. A really nice smoked paprika, whole cardamom pods (both green and black), and Tellicherry peppercorns are just a few options that immediately come to mind, as are the notoriously expensive vanilla beans and saffron threads.
If the stocking owner is trying to get into a particular regional cuisine, buy the spices that they’ll most likely be needing. Give sumac if they’re just getting into Middle Easter cuisine, whole dried peppers for Mexican, or Makrut lime leaves for Thai. (Bonus: The lime leaves will make the stocking smell amazing.) If your target is really into baking, get them some Ceylon cinnamon, a fancy vanilla paste they would never buy for themselves, or a jar of whole nutmeg.
This is, of course, an incomplete list of the nice spices you could put in someone’s stocking. If their area of culinary interest isn’t reflected above, a quick internet search is all it takes to find the spices that are key to a particular cuisine. Then, it is simply a matter of buying the thing. And if nothing else, you can always stuff their stocking with really nice salt. Both Maldon and Jacobsen sell their flake salt in little pinch tins, and those never fail to delight.