Drinking from a firehose

I had never heard of stoemp, but the recipe looks fantastic, and I think I can make it vegan without too much trouble. Let me ask--is the cream 100% necessary, or do you think I could use a cashew milk? I'd imagine I might need to reduce the amount, slightly, as it wouldn't thicken, or perhaps put in the teensiest bit of cornstarch to thicken it? (I'm assuming the ultimate goal is a thicker, creamier texture.)

Anyway, I'm intrigued, and I thank you for sharing the idea because I am always looking for new ways to eat vegetables, and I'm not particularly familiar with how to prepare leeks. :-)