In the southern states of the US, collard greens are often cooked in chicken stock with bacon or ham. This is a vegetarian version of that traditional dish. It also works with other robust, big-leaved brassicas, such as kale and spring greens.
Remove the toughest stalks from the collards and shred the remaining leaves. Heat the oil in a large pot over medium heat. Saute the onions until slightly softened, about 2 minutes, then add the chilli flakes and garlic and cook another minute. Add the collard greens and cook another minute. Add the vegetable stock, cover and bring to a simmer. Cook until greens are tender, about 20 minutes. Season with salt and freshly ground black pepper.
2 tbs olive oil (or mixture of oil and butter if you're not vegan)
1/2 large onion, chopped
1 tsp chilli flakes
1 clove garlic, finely chopped
Bunch collard greens
400ml vegetable stock
Salt and freshly ground black pepper