Heat the oil on medium-high head in a large frying pan and add a dash of cayenne (if using).

When the oil is hot and shimmering, but not smoking, add the onion and cook until it is translucent.

Turn the heat down to medium and add greens, stirring constantly. When the greens have turned bright “army” green, turn off the heat.

Add the vinegar and some salt and pepper. Stir to mix and then drizzle the honey over and give it one last stir. Serve immediately.