Chard and spinach are v similar, I like steamed or chopped and cooked down with chili and garlic in the frying pan on low heat with a touch of oil.
Kale- have heard its lovely baked (not sure how you'd do this but worth googling) it is supposed to make a cheesy crisp type thing apparently. I tend to toast some pine nuts and then dry fry the kale. When it goes a bit crispy I toss in the nuts. It is also v nice cooked with a splash of raspberry vinegar and sesame oil.
My other fave is steamed green beans which you then add to caramelised red onions and cherry tomatoes, add to pan and splash on balsamoc then llow to fry down until toms are squishy and vinegar is gone. This is lovely served as a warm salad and you can add asparagus too- yummy!
Celeriac? Grated with a nice dressing or as a creamy soup.
Jerusalem artichoke, artichokes, watercress, pak choi oh the list goes on. I recommend the Sophie Griggson vegetable book. It might be Jane Griggson, can't remember but loads in there
