Compound butter? What the hell is that? Chill. It’s a cheffy name for ingredients creamed into butter. It’s brilliant when added to pretty much anything: grilled chicken (as in this recipe) or vegetables (broccoli, aubergine, asparagus) cooked on a griddle pan or over a fire. Even a juicy piece of beef would be up for it. The recipe below doesn’t require all of the butter, so store the rest in your fridge.