In a heavy bottomed pot melt the butter and sauté the onion without colour until it is soft. Add the Meadow mushrooms and cook until there is no more liquid in the pot. Add the potato, Simon Gault Home Cuisine Moroccan seasoning, water and Simon Gault Home Cuisine vegetable stock. Bring to the boil and simmer until the potato is cooked (roughly 5-8 minutes). Add the cream and bring to the boil again then add the coriander. Remove from the heat and place mixture into a blender and purée until smooth. Stir through the orange zest and season to taste. Pour into soup bowls and serve. Garnish with crème fraîche or plain Greek yoghurt.