I love me a plate of boerenkool met worst!
It's a very popular winter dish in the Netherlands. Basically all you have to do is boil an even amount of potatoes and kale in a big pot. Boil it for 20-30 minutes and then mash it all together as if you're making mashed potatoes.
What's delicious too is fry some bacon and crumble it into the dish once it's done!
I like a table spoon of white vinegar on mine but you can do gravy or whatever floats your boat. The sausage you can substitute with bratwurst, hot dogs or whatever since wwe don't have Unox sausages in the USA either