Jerusalem artichoke, wild mushroom and truffle soup Serves: 6 Ingredients 150g wild mushrooms truffle oil 100g butter 1 white onion, finely diced 3 cloves garlic, finely chopped 2 sticks celery, sliced white of 1 leek, shredded 500g artichokes, peeled and sliced (keep under cold lemon water) 1 litre vegetable stock salt and pepper to taste