If using cultivated mushrooms, they should all be quartered. Ceps will need to be sliced, trompettes halved and girolles left whole or halved if large.
Heat a frying-pan with the olive oil. Add the mushrooms and Spring onions and sauté for a few minutes. Mix the mushroom ketchup or essence with the groundnut oil, a squeeze of lemon and the vinegar. Season with salt and pepper and