looking for a cardamom concentrate, but having trouble finding it in concentrate here in the UK.
Looks like they got it here,
Flavourart E Liquid Flavouring - Diy E Liquid
Some notes on it too from HIC on another forum:
FA Cardamom: roughly 3%, but nearly always 1% or less in recipes
No other company makes this spice flavor; fortunately FA did it perfectly! This tastes just like sweet green cardamom powder (not black cardamom).
If you're not familiar with cardamom, it's a sweet spice related to ginger. It tastes similar to a combination of ginger and cinnamon. It's the distinctive flavor in real Indian chai. If you vape coconut, fruit flavors, chai/tea, or spiced bakery recipes, you need this flavor.
Cardamom adds a great touch to many fruits. If you use coconut in any recipe, try it with Cardamom. They are a perfect pair, whether in dessert, coffee, tobacco, or fruit mix recipes. The same can be said for mango, peach, pear, apple, and citrus. If you like vaping those flavors - especially in bakery recipes - you must try with Cardamom.
Of course you need Cardamom for authentic flavor in chai. It's also used in many Indian desserts and Scandinavian cookies.
If you're bored with your usual vapes, try adding 0.25-0.5% Cardamom to a couple recipes for an exotic, sweet-spice touch. If you really can't stand ginger, you should probably avoid Cardamom - but otherwise, give it a try.