Mushroom à la Crème

• ½–1 oz (15–30 g/⅛–¼ stick) butter
• 3

Melt the butter in a heavy saucepan until it foams. Add the chopped onions, cover and sweat on a gentle heat for 5–10 minutes or until quite soft but not coloured; remove the onions to a bowl. Increase the heat and cook the sliced mushrooms in batches if necessary. Season each batch with salt, freshly ground pepper and a tiny squeeze of lemon juice. Add the onions and chives to the mushrooms in