5 issues of BBC Good Food for £5
Put a wok or frying pan over the heat while you thickly slice the mushrooms. Tip the butter into the pan and when sizzling add the mushrooms and cook over a high heat, stirring occasionally until the mushrooms are tender and juicy.
Meanwhile toast and lightly butter the bread and put on 2 plates.
Stir the mustard and some salt and pepper into the mushrooms with 4 tbsp of the soured cream and, when lightly mixed, pile the mushrooms and their creamy sauce on the toast. Spoon the last of the soured cream on top, snip over the chives and grind over some black pepper.