Preheat Oven 170°C, line 2 baking trays with parchment paper
Cover the porcini's in 370ml just boiled hot water and soak for 10 minutes.
Spread the Portobello strips onto one of the baking trays. Spread the button mushrooms on the second baking tray then spread the shiitakes in the spaces between the button mushrooms on the same parchment-lined baking tray. Bake all the mushrooms in the preheated oven for 15 minutes.
With 5 minutes left on soaking the porcini's fry the onions with the olive oil in a large saucepan [at least 2.5L] on a medium to low heat for 2-3 minutes or until lightly browned. Stir the onions regularly to prevent them burning.
Strain the porcini's into a fine mesh sieve over a bowl to reserve the liquid. If there is grit in the liquid you may need to use muslin in the sieve and strain again.
Add the strained porcini's, celery, garlic and thyme to the onions in the saucepan and then fry for a further minute, stirring regularly.
Add the stock and reserved mushroom liquid, bring to the boil and simmer for 8 minutes, with the lid on the saucepan.
In the meantime, as soon as the mushrooms in the oven are ready, remove from the oven and immediately add to the saucepan. Be careful opening the oven door as steam can escape, wear oven gloves and keep your face and body at a distance.
Remove the soup from the heat and add the balsamic vinegar and fresh basil.
Blend in a high-speed blender until smooth. Season to taste. Add more stock if you prefer a thinner consistency.
Reheat in the saucepan then pour into bowls and serve with a drizzle of the coconut cream, pepper and chopped basil.