stalks, tearing them as you go to break them up a little. Cook over a high heat for 5 minutes, turning the mushrooms over half way through, until they are golden and juicy.
Meanwhile toast the bread in a toaster or under the grill and when ready, spread with the remaining butter.
Take the mushrooms from the pan (leave the stalks behind) and put them cup side up in a shallow heatproof dish. Now tip the spinach into the pan with the stalks and stir it around in the buttery juices for about a minute, just until it wilts. Pile the mixture onto the mushrooms, cover the spinach with a slice of cheddar and flash under the grill until the cheese just melts. Serve each mushroom on a slice of the buttered toast and spoon over the juices.
