You need advice from a former cabbage hater. I hated it so much as a child I stored it up over night in my cheeks as I refused to swallow it and didn't want my parents to know.
Happily, Curly kale certainly can't be described as slimy, that's for sure.
I am growing nero kale for the first time this year and looking forward to it, so can't comment on that, other than it tastes stronger by all accounts. Only grew red russian for one year a long time ago, and I really didn't like it. Not what I would give a non cabage eater.
So, that leaves curly kale. I think there is a a reason why the former animal fodder has become so prevalent in supermarkets. Basically huge numbers of people like it. But like sprouts, it's all about how you cook it.
The growing is pretty straight forward, and very very productive over the longest of seasons.
Strip the leaves from the possibly "woody" stalks, and then chop the leaves, so as not to give the cabbage hater a chance to moan at the long sinews. Saute/steam in a little olive oil with sesame seed and soy sauce. Serve it as a proper proud side dish, as just crisp to cooked. Heavenly. I often mix with a few chopped walnuts. There is absolutely nothing a cabbage hater could dislike ... well, as long as the caterpillars aren't lurking. Alternatively, bubble and squeak is ok too, but "hiding" ingredients isn't going to be a long term solution.
![biggrin :D](https://chat.allotment-garden.org/Smileys/green/biggrin.gif)
I've always got some curly kale on the go all year round, it's so easy to grow, and actually is very versatile, unlike some cabbage. It's the texture that's the winner, and you would have to be a pretty poor cook to make it slimy.